iCloud options

Using the iCloud pane, you manage your details for Apple's iCloud service and also the components that are activated on your Mac. If you haven't signed in, the pane will simply be two fields - Apple ID and password - and a Sign In button.

Once signed in, you'll see your avatar, username and iCloud email address to the left of the pane, along with Account Details and Set Up Family/Manage Family buttons.

How to use System Preferences in macOS Sierra

Click Account Details and type in your password to gain access to a sheet that enables you to edit the following: your name (under the General tab); email addresses and other means of contact, primary postal and email marketing preferences (Contact); security details, including your birthday, password, security question, and rescue email address for an emergency account reset (Security); Apple equipment using this Apple ID (Devices-requires verification to access); and primary payment method (Payment).

Set Up Family/Manage Family, respectively, enable you to set up or manage family sharing. In the Family Members tab, use the + button to add new family members by sending them an email invite. For a child without an account, you can create a new Apple ID for them.

To remove a member from sharing, select them and click the - button. You can also stop family sharing entirely by clicking Stop Family Sharing and then confirming this choice in the sheet that appears.

The My Apps & Services tab is new to macOS High Sierra, and enables you to fine-tune how apps and services are shared. In each case, select a category from the sidebar, and make your adjustments accordingly.

The four categories are Purchase Sharing, Apple Music, iCloud Storage, and Location Sharing. iCloud Storage is notable, because it enables family members to share iCloud space, rather than everyone paying individually. And although location sharing isn't new, it is new to the Mac - previously, permission for this was granted in iOS apps.

Back in the pane itself, the larger right-hand area enables you to activate or deactivate various services and data types iCloud can share between your devices: iCloud Drive (click Options to see an apps list); Photos; Mail; Contacts; Calendars; Reminders; Safari (bookmarks and open tabs); Notes; Siri; Keychain (passwords and payment data); Back to My Mac; Find My Mac.

Underneath, a bar details the status of your iCloud storage, for which Apple provides 5 GB for free (and, we think, could do with being a bit more generous). If you need more space, click Manage and you can delete existing back-ups from iOS devices, or specific app data.

Alternatively, click Buy More Storage and select an option to change your iCloud storage plan. For 79p monthly, you get 50GB in total; £2.49 gets you 200GB; for £6.99, you get 2TB. You can later downgrade if you no longer need the extra storage. Depending on your location, you may receive a partial refund for any time left to run on your current subscription plan.

How to use System Preferences in macOS Sierra

If you decide you don't want to use iCloud at all on your machine, click Sign Out. However, if you're using an iCloud account and password to log in to your Mac, you'll then have to click Stop Using iCloud and create a new password specifically for the Mac.

Internet Accounts options

The Internet Accounts pane defines your online accounts at the system level, enabling services and apps to hook into them with your permission, potentially saving you typing in the same usernames and passwords time and time again. If you've set up iCloud already on your Mac, it will appear in the sidebar. To the right, you'll see a list of popular services you can add an account for.

To add a new account, click on a logo and a sheet will ask for information that's relevant for that particular service (usually a username and password, but sometimes other details too). On adding your details and clicking Next, you may see an overview regarding what the service will be allowed to do with your data. For example, signing into Twitter allows you to post photos and show links from your timeline in Safari; sign into Facebook and data will be integrated with Contacts and Calendar.

How to use System Preferences in macOS Sierra

Once accounts are created, they can be selected in the aforementioned sidebar. Doing so loads their information into the area where the service buttons are otherwise displayed, enabling you to update their configuration. For example, Facebook provides the means to disable the account or just its connection to Contacts and Calendars, along with buttons for grabbing new profile photos and updating your password and account description. Twitter has a button for updating details in Contacts, and text fields for updating your password and account description.

Any configured email accounts give you settings for updating the name, description and password, and apps the account is used with; behind an Advanced button, there's the means to update other aspects of the account's details, such as its IMAP hostname, the port used, and whether the account uses SSL.

To delete one of the accounts entirely, select it in the sidebar and click the '-' button. Be aware that in many cases, deleting an account may remove data from relevant applications. Facebook offers a more nuanced approach: you get the choice of deleting Facebook contacts or keeping them, even if the account itself is removed.


Extensions enables you to control and enable/disable installed Apple and third-party extensions that can be used to customise your Mac. You select a category (All, Actions, Share Menu, and so on) from the left-hand side of the pane, and relevant items are then listed on the right-hand side. Each can be activated or disabled, respectively, by checking or unchecking its checkbox.

Available categories and extensions will depend entirely on what applications you have installed on your Mac. A new Mac will lack third-party extensions. However, install the likes of Dropbox and Fantastical and you'll see additional options. Photos lists installed extensions for editing photos.

How to use System Preferences in macOS Sierra

The item categories are straightforward. All lists all installed extensions and groups them by app. Actions lists content extensions, such as Apple's own Markup, used for annotating imagery in compatible applications (like Mail and TextEdit) when you hover the cursor over an image and select Markup from the pop-up menu. Finder lists extensions that directly integrate with Apple's file manager, such as Dropbox. Share Menu enables you to control what appears in the Share menu found in supported apps, like Safari and Finder. And Today determines which widgets are available in Notification Center's Today view.

In all cases, disabling an extension in System Preferences immediately makes it unavailable system-wide. Note that app-specific extensions, such as those for Safari, are not yet listed in this pane.


The Bluetooth pane is used for controlling any Bluetooth devices your Mac is paired with. Using the button under the huge Bluetooth logo, you can turn Bluetooth on your Mac on and off; when it's active, your Mac's name is displayed under the button. (You may need to know it when trying to connect certain hardware.)

The main part of the panel lists devices paired with the computer and their current status. Hover the cursor over an item and a cross button appears, which when clicked removes the item from the list. Note that if you remove an item and then want to use it later, you'll need to pair it again with your Mac.

At the bottom of the pane is a checkbox that enables you to show Bluetooth in the menu bar. This menu extra provides a faster means of turning Bluetooth on and off, along with enabling you to connect/disconnect hardware and ascertain its battery level. It can also be used to send files to connected devices and browse files already on them.

How to use System Preferences in macOS Sierra

The Advanced button provides a few further options: opening Bluetooth Setup Assistant if no keyboard is detected at startup; doing the same if no mouse or trackpad is detected; and allowing Bluetooth devices (such as a keyboard or mouse) to wake the computer.

How to use System Preferences in macOS Sierra


The Sharing pane opens up various aspects of your Mac to other computers on the network. The top of the pane shows the computer's name, which is editable, and the left-hand section lists services available for sharing. Tick a checkbox to activate the service. On selecting a service (regardless of whether it's active), its options appear to the right.

DVD or CD Sharing enables you to share a built-in or connected optical drive across the network. This is useful if you've a new Mac lacking a drive but an older one that happily takes CDs and DVDs. Note that data sent between machines is not encrypted and you can have the computer alert when someone else tries to use the drive.

Screen Sharing enables the Mac's screen to be shared. The 'Allow access for' section of the main pane provides control over who can access the shared screen: all users, or specified users and groups, added or removed using the + and - buttons. The 'Computer Settings' button provides access to allow anyone to request access, and to allow VNC users control with a specified password. When Screen Sharing is active, the shared Mac can be found under 'devices' in the Finder sidebar of other machines; clicking 'Share Screen…' begins the sharing process.

Here's how to manage Macs on a Windows-based network.

How to use System Preferences in macOS Sierra

File Sharing activates a Mac's Public Folder, which has a Drop Box into which anyone on the network can drop files. (Once sent, said files are not visible to the sender.) The 'Options…' button in the System Preferences pane opens a sheet with settings for activating or deactivating connection types, and the 'Shared Folders' and 'Users' panels, respectively, optionally enable you to share additional folders and provide various access types to specific users or groups. Connect via Finder (select the computer in a networked Mac's Finder sidebar, then click 'Connect As…') with relevant username/password credentials and you can navigate all of the files/folders for the relevant account.

Printer Sharing provides the means for sharing a connected printer across the network. Aside from a button to open the Printers & Scanners pane, there are panels for printers you can share and to state which users are allowed access.

Remote Login enables someone to log in to the Mac from another computer on the network, using SSH and SFTP. Again, you can define access privileges for individuals or groups.

Remote Management works with Apple's Remote Desktop, and is designed for people having to manage a network of Macs. There's the familiar field for setting user access, but it has an additional Options button (also seen when Remote Management is activated), which enables you to select tasks remote users are allowed to perform. Click 'Computer Settings…' and a sheet provides checkboxes for: showing Remote Management status in the menu bar; determining whether anyone may request permission to control the screen; and stating a password for VNC viewers. Four fields can have information added for display in a System Overview report.

How to use System Preferences in macOS Sierra

Remote Apple Events, when activated on a Mac, allows applications on other Macs to send Apple events to it. An event is a task being performed on a Mac, such as opening a document or printing. So with this option activated, an AppleScript running on another Mac on the network could potentially open and print a document on your Mac.

Internet Sharing makes it possible to share a Mac's internet connection from the source selected in the menu to another Mac's port, the type outlined in 'To computers using'. (Sources, such as Wi-Fi and Ethernet will vary by Mac.) This can be useful for computers lacking connectivity, for example, sharing your Mac's Wi-Fi connection over Ethernet to an old or damaged machine.

With Bluetooth Sharing active, the Mac can share files with other Bluetooth enabled devices. The first two menus determine what happens when files are received (Accept and Save, Accept and Open, Ask What to Do, or Never Allow), and where accepted items are saved. The second set of menus determines what happens when other Bluetooth devices browse the Mac. You can choose from Always Allow, Ask What to Do and Never Allow, along with selecting a folder others can browse.

How to use System Preferences in macOS Sierra

Content Caching is new to macOS High Sierra. It's designed to save bandwidth by storing local copies of specific content types (including app and OS updates - Apple provides a full list), which can subsequently be shared locally with 'client' devices (other Macs, and also iOS devices).

To turn on Content Caching, click its tickbox in the Sharing sidebar. In order to share content to iOS devices, you'll also need to tick 'Share Internet connection'. Note that the USB devices will need to be connected to the Mac via USB. (Apple also recommends the Mac sharing content be connected to the internet via ethernet, and be plugged into the mains.)

Click the Options button to determine how large the cache size can get (it defaults to Unlimited, which you might want to reduce if your Mac hasn't got tons of space to spare). The cache location also starts out as your boot volume - and is best left that way - but you can select alternate volumes if you wish.

Network settings in macOS Sierra

The Network pane is where you define network settings, enabling you to connect to the likes of wireless routers or corporate ethernet. It's one of the more intimidating System Preferences panes, due to the sheer number of available settings and its relative complexity. However, the vast majority of users will rarely if ever have to venture into it, since more often than not just typing in a Wi-Fi password is all the networking effort most need to make.

How to use System Preferences in macOS Sierra

The pane is essentially split in three. At the top is the Location menu, which defaults to Automatic, but which can be used to define specific set-ups for different places, such as home, work, or regular overseas haunts. The left-hand pane lists available connection types (or 'services' in Apple language), and the largest part of the pane outlines the status and settings related to the currently selected service. The foot of the window houses three buttons: 'Assist me…', Revert and Apply.

If you only ever use your Mac in one place, with one connection type, there's no need to use Location. However, if your Mac needs to connect to multiple networks with settings that are more complex than simply selecting a different Wi-Fi network from the menu bar, defining multiple locations makes sense.

To do so, select the menu and then 'Edit Locations…'. Use + to add a new location, - to delete an existing one, and the cog button to duplicate or rename the currently selected location. With more than one location defined, a Location menu appears in the system-wide Apple menu; selecting an option there is usually faster than using the equivalent menu in System Preferences.

How to use System Preferences in macOS Sierra

As noted, the left-hand pane lists available services, such as Wi-Fi, Ethernet and FireWire. (The specifics will depend on your Mac's hardware.) A traffic light system denotes the status of a service: green for connected, red for off, and yellow for when on but not connected for some reason. On the last of those, text beneath the service's name may list a reason for the lack of connection.

The bottom of the pane has + and - buttons for, respectively, creating and removing services. On creating a new one, you choose an interface type and the service's name. Deletion is immediate but can be undone using the Revert button. The cog button enables you to duplicate or rename the selected service, or to make it inactive. You can set the service order, to prioritise certain connection types. The other options include the means to import and export configurations, and Manage Virtual Interfaces, for editing a list of such interfaces.

How to use System Preferences in macOS Sierra

Any time one of the services is selected, its status and relevant configuration menus are listed in the large pane to the right of the services list. For example, select Wi-Fi and you'll see its connection status, a button for turning it on and off, and details regarding the network's name and the Mac's IP address.

Below this, there's a menu for selecting networks, a checkbox that determines whether the Mac asks to join new networks rather than connecting to known ones automatically, a checkbox for showing Wi-Fi status in the menu bar, and an 'Advanced' button. By contrast, select Ethernet and you'll get the service's status and the means to configure network settings. 'Using DHCP' is the default, but choosing 'Manually' provides fields for inputting IP address, subnet mask and router details.

The Advanced button opens a multi-tabbed sheet that enables you to drill down into the fine detail of network connections. Available tabs will depend on the selected service, but may include: Wi-Fi, TCP/IP, DNS, WINS, 802.1X, Proxies, Hardware and Bridge Status.

How to use System Preferences in macOS Sierra

The Wi-Fi tab is the one users are most likely to need at some point. It enables you to reorder known Wi-Fi networks, and it's best to drag most-used ones to the top, to avoid your Mac wasting time first searching for the others when trying to connect.

You can select and delete any you no longer need (such as temporary airport, cafe and hotel connections you're unlikely to use again). The 'Remember…' checkbox when ticked makes it quicker to access a network previously joined (albeit with the potential to clutter the list, as already mentioned). Subsequent checkboxes are primarily concerned with restricting network meddling by users, and are only worth activating in locked-down environments or for accounts created for inexperienced users.

TCP/IP is the protocol used to connect your Mac to the internet. Generally, connections will be automatic. However, if you've been provided IP, subnet mask and router details to manually input, this is where you do so. The tab also includes a 'Renew DHCP Lease' button, which is worth knowing about, because it forces your Mac to renew your current IP address; this can be useful in circumstances when there are many devices on the network and there's a clash that kicks your Mac off of a previously stable connection.

DNS server details are generally provided automatically. DNS is how computers associate domain names (like www.macworld.co.uk) with numerical IP addresses. Some people prefer to override default DNS settings with the likes of Google Public DNS ( and, which can under some circumstances be faster. There are also services for circumventing geolocation blocks through using specific DNS settings, thereby enabling you to access online content restricted to specific countries or get around blocking in certain territories. The DNS tab is where you'd add such settings.

WINS may be required if you connect to remote networks that use NetBIOS names; 802.1X is used to control access and beef up security, and network admins will advise when you need to add or amend a profile; and proxies can be used to filter internet traffic - again, something only likely to be required in corporate environments, with you being assisted by an admin. Hardware displays your MAC Address network identifier, and has a Configure menu that when set to Manually enables you to adjust the MTU (Maximum Transmission Unit) setting.

When any changes are made, click Apply to confirm them. Now imagine the next line is in three-metre-high neon letters with a klaxon blazing alongside: do not make any changes to your network settings - and especially the more esoteric ones - unless you know what you're doing. This isn't a pane to mess about in, and you could find your Mac rather rapidly disconnected from the web and very alone on your office desk.

Still, if things do go wrong, clicking 'Assist me…' might help. You get two options here: 'Diagnostics…' provides checks regarding your current settings, attempting to squash any network issues your Mac might have; and 'Assistant…' launches Network Setup Assistant, for walking you through the process of creating a new internet or local network connection. This option appears to be absent as of macOS High Sierra.

How to use System Preferences in macOS Sierra

Setting up Touch ID in System Preferences

Guide to Mac System Preferences: Touch ID

If your Mac has a Touch ID sensor (found towards the right of the Touch Bar on the 2016 MacBook Pro), a Touch ID pane will appear in the last row of System Preferences.

Guide to Mac System Preferences: Touch ID

At the top of the pane are stored fingerprints - and you may already have one from when you set up your Mac. Regardless, 'Add a fingerprint' begins the process of adding another. Enter your admin password and follow the prompts - which mostly involve raising and lowering your digit. When everything's finished, click Done.

Guide to Mac System Preferences: Touch ID

Up to three fingerprints can be stored. Any existing one can be renamed by clicking the label below it and typing something new. A print can be deleted by hovering over it, clicking the cross, and confirming your decision - which cannot be undone. We'd recommend adding your thumbprint and also a print for an index or ring finger: whichever can naturally and easily reach the Touch ID sensor when your hands are in a standard typing position.

Below the prints are tickboxes that determine when Touch ID can be used on your Mac; for unlocking it, using Apple Pay, and enabling purchases within iTunes, the App Store, and iBooks. Should you deselect any of these boxes, access/confirmation reverts to how it works on Macs without Touch ID, such as typing your password to unlock your Mac.

Users & Groups in System Preferences

The Users & Groups pane is where you create and modify accounts for the current Mac. Even if the Mac has only one user, the ability to create new accounts can come in handy for troubleshooting; however, for any Mac used by multiple parties, understanding Users & Groups is extremely important from a security and Mac maintenance standpoint.

The pane has a padlock at the bottom. In order to make any changes to the pane's settings, click it and enter an administrator's username and password.

Accounts are listed in the left-hand sidebar. The current user is displayed at the top, and the others beneath, in the section 'Other Users'. For each user, you're shown their login image, account name, and account type.

Select the current user's account; the right-hand section of the pane will offer two tabs: Password and Login Items. Click Password and you'll see the account's icon, which you can click to edit. A new image can be chosen from a built-in selection or from whatever you have in Photos.

How to use System Preferences in macOS Sierra

Click the 'Change Password…' button if you want to update the account's password. If the account uses an iCloud password (which ceased to be an optionb in macOS Sierra, you'll get the option to use a separate password or to change the iCloud one; on updating a password, you'll need to enter the old one, compose a new one, verify the new one, and add an optional hint. Any hint should be quite vague - do not type in something too close to the actual password, if you want your Mac to remain secure.

At the bottom of this tab is a button for opening the Contacts card for the current account, and some checkboxes; these denote whether the user can reset their password using an Apple ID, whether the user can administer the computer, and whether parental controls should be enabled. These checkboxes will be greyed out (and therefore cannot be changed) unless the current user is an administrator.

How to use System Preferences in macOS Sierra

Under the Login Items tab, you'll find items that automatically open when the account logs in. Quite often, background utilities will be found here. New items can be added using the '+' button and choosing an item from the sheet. Applications are the most common login items, although you can also select documents. Existing items can be removed by selecting them and clicking the '-' button.

Too many items in the list may result in slower Mac start-ups and potentially even system conflicts. If there's something in the list you don't recognise, search for it online and if you deem it unnecessary, delete it from the list.

When an administrator is logged in, they have some control over other accounts. On selecting one from the Other Users section in the sidebar, they can perform a password reset, allow admin accounts to reset the account password using an Apple ID, and toggle admin status/parental controls. Note that if another user's account is currently logged in, it cannot be selected in the sidebar.

How to use System Preferences in macOS Sierra

Administrators also have access to the controls at the foot of the sidebar, which are for defining login options, and for creating/deleting accounts. Select Login Options and you will see a number of things that can be changed. Automatic login is on by default for a new Mac, but is best disabled for security reasons; doing so forces a password to be entered when logging in.

Beneath this is a setting for how the login window appears. The default shows a list of users, one of which is clicked before a password is entered. 'Name and password' is plainer and a little more secure, since you must enter both the username and password.

How to use System Preferences in macOS Sierra

Five tickboxes then provide a range of further settings for the login window and account management.

Show the Sleep, Restart, and Shut Down buttons displays those buttons on the login screen; Show Input menu in login window displays on the login screen the menu that enables you to switch languages (and therefore also keyboards), which is useful if people using the Mac require and are used to different keyboard layouts; Show password hints determines whether hints are shown when a password is forgotten; Show fast user switching menu provides options to place a switching menu in the OS X menu bar, and this can be displayed as the account's full name, account name, or just an icon; and 'Use VoiceOver in the login window' is self-explanatory.

A button beneath the tickboxes provides the means for entering the address of an Open Directory Server or Active Directory Domain during login.

How to use System Preferences in macOS Sierra

Creating & deleting accounts

Below Login Options are '+' and '-' buttons, which, respectively, are for creating and deleting accounts. Click '+' to open the new account sheet, in which you must first define the type of account: Administrator, Standard, Managed with Parental Controls, or Sharing Only.

In all cases, you need to provide a full name for the account, an account name (macOS will automate this - turning the likes of Name Surname into 'namesurname' - but this can be overridden; the result will be the name of the account's home folder), and decide on the password that's to be used. Prior to macOS Sierra, this could be either an existing Apple ID/iCloud password or Mac-specific one. As of macOS Sierra, only the latter is an option. Click 'Create User' and the account will usually be created within a few seconds. Creating a new account can also be a good idea if your Mac is being strange. Login to the account and see if the same issues occur; if not, they're most likely related to something on the original account; if so, some other problem is to blame (such as dodgy hardware or software).

Note that within the 'New Account' menu there's also a Group option, which only requires a name to be entered. On creating a group, you add existing users as members. You can then elsewhere assign shared file access privileges to the group.

To delete a group, select it, click the '-' button and then confirm your choice. To delete an account, select it, click the '-' button, and then decide what you want to do with the account's home folder that contains all of the user's documents and data. You can save it to a disk image, leave the folder in place, or delete it entirely. On making a decision, click Delete User and macOS will perform the chosen action.

Note that if you're backing up your Mac, deleting someone's home folder may remove it from the backup, and so only choose 'Delete the home folder' if you're certain you (and/or the account owner) no longer needs access to the data within.

How to use System Preferences in macOS Sierra

Finally, the cog icon when clicked enables you to set a master password for FileVault, which can be activated in the Security & Privacy System Preferences pane. If the password is forgotten, encrypted data within FileVault will be inaccessible.

Parental controls

This System Preferences pane is for restricting accounts. Although it's primarily designed to limit a child's access to certain apps, the web, or the entire Mac, its various options have scope for wider use, for example with the guest account.

You'll need to click the lock and enter admin details to make any edits inside Parental Controls. Prior to working on an account, you can optionally check 'Manage parental controls from another computer'; this makes it possible to define any given Mac's parental control settings from the Parental Controls System Preferences pane on another Mac, assuming you have relevant admin details for the remote computer.

If there are no accounts to manage, you can create a new user account with parental controls or convert the current account. If the current account is the sole administrator, you will first be prompted to create a replacement account.

In theory, the pane should pick up existing accounts that can be managed, but if it doesn't, select the account in the Users & Groups pane, tick 'Enable parental controls', and then click 'Open Parental Controls'. You should now see the Parental Controls pane with accounts in a sidebar. If not and you still get the entry screen, quit and restart System Preferences and reopen Parental Controls.

How to use System Preferences in macOS Sierra

From the sidebar, you can then select the Guest User account or any standard accounts on the Mac. Admin accounts cannot have parental controls assigned to them. If other networked computers allow controls to be managed remotely, they will be listed below the current computer's accounts.

Using the '+' and '-' buttons at the foot of the sidebar, you can add a new account or remove an existing one, just like in Users & Groups. The cog button provides access to a menu for turning parental controls on/off for the current account, copying its settings, or pasting previously copied settings.

On selecting an account, you will see six tabs: Apps, Stores, Web, Time, Privacy and Other.

How to use System Preferences in macOS Sierra

The Apps tab's first option is Allow use of camera. This when disabled prevents the user accessing built-in cameras and also cameras in connected displays, but not those connected via USB.

The next two boxes, which are pre-checked, allow the user to join Game Center multiplayer games and add Game Center friends. Next, Limit Mail to allowed contacts when active restricts the user to contacting (via Mail) only specific approved email addresses. Click Manage to open a sheet for adding these contacts.

You can optionally check Send requests to and then type your email address in the adjacent field. On doing this, any attempts by the user to send an email to a non-approved email address will be sent to you. To populate the approved list, use the '+' button to add contacts. As you begin typing in a name, OS X will make suggestions based on people already in the Contacts app. Use the down cursor to select one such name and Return to confirm; alternatively, you can manually type a name and then tap Tab to add the email address. Once you have a list, select any name and hit '-' to remove it.

Limit Applications on this Mac, when active, provides the means to restrict the selected account's access to apps. Said apps can be defined in the Allowed Apps list.

Web is about defining website access restrictions. 'Allow unrestricted access to websites' makes no changes at the system level. 'Try to limit access to adult websites automatically' attempts to do what its description says, and enables you to use 'Customize…' to always allow or never allow specific sites. We should note that automated filters are problematic, and often end up with false positives while letting many sites through the net. For younger children, supervise their web-browsing sessions, or make use of 'Allow access onto only these websites', which blocks anything not on the list below. This is predefined with a number of safe sites, but you can remove any of them and/or add your own.

Stores provides the means to individually disable the iTunes Store, iTunes U and iBooks Store. Further settings make it possible to restrict specific types of media: music with explicit content; movies up to a defined age rating (U, PG, 12, 15, 18); TV shows, Apps (4+, 9+, 12+, 17+), and books with explicit sexual content. Be mindful that Apple can be quite conservative with app ratings - apps that enable web browsing often end up as 17+; and so you may be better off using the Apps section to specify which apps the user has access to.

How to use System Preferences in macOS Sierra

Time is for defining access to the Mac as a whole. Using the checkboxes, separate usage limits can be set for weekdays (Monday through Friday) and weekends (Saturday and Sunday), and these are initially, respectively, three and five hours. 30 minutes is the minimum setting for both, and eight hours is the maximum. With the Bedtime checkboxes, you can prevent access during defined hours for 'School nights' (Sunday night through Thursday night) and 'Weekend' (Friday night and Saturday night).

How to use System Preferences in macOS Sierra

Privacy limits access to the user's data. The 'Manage Privacy' button takes you to the Privacy tab within Security & Privacy. The 'Allow changes to' checkboxes let you lock existing settings for specific data types and services, preventing apps from making any changes to them.

How to use System Preferences in macOS Sierra

Other is a grab-bag of functions and features you can turn on or off, depending on the user and your own preferences. 'Turn off Siri & Dictation' blocks enabling Dictation in the Dictation & Speech System Preferences pane and Siri in the Siri pane. If 'Disable editing of printers and scanners' is on, the user cannot adjust printer and scanner settings. 'Block CD and DVD burning in the Finder' stops the user burning a CD or DVD - as if any kids would want to do that these days anyway.

How to use System Preferences in macOS Sierra

Restrict explicit language in Dictionary is one for the purists, blocking so-called 'inappropriate' content in the Dictionary app and related sources OS X may leverage, such as Wikipedia. 'Prevent the Dock from being modified' stops the user changing the Dock in any way.

And Use Simple Finder gives the user a simplified desktop, aimed at the young or inexperienced. This disables windows in Finder, and only allows access to apps you define within the Apps tab of Parental Controls. The Dock is restricted to three folders: My Applications; Documents; Shared. A user whose account is set up to use Simple Finder can only switch to the full version of Finder via Finder > Run Full Finder when armed with admin details.

How to use System Preferences in macOS Sierra

Finally, the 'Logs…' button opens a sheet that details app and web activity. Said activity can be shown for 'today', 'all', or time periods ranging from a week to a year. The two tabs, 'Applications' and 'Web', provide access to relevant lists and charts. Selected items can be opened using the 'Open' button.


Siri was introduced to the Mac with macOS Sierra. It enables you to talk to your Mac and have it perform basic tasks. In the System Preferences pane, Siri can be enabled or disabled using the 'Enable Ask Siri' checkbox under the large Siri logo.

To the right, options exist for fine-tuning how Siri works, and how you interact with the feature. You can change the keyboard shortcut used to trigger Siri, and switch to a different voice input, depending on what microphones are available.

Under 'Language', you can switch to a different language. By default, this setting will be based on the language chosen for your Mac, and the same is true for Siri Voice. However, you can temporarily - or permanently - select a new language at any point, and many of these offer variants. For example, there are four versions of Chinese, three of German, and a whopping nine of English.

On selecting a language, the Siri Voice menu updates automatically to list suitable choices. With English, you can switch between British, American and Australian voices, each of which offers a male and female variant.

The final two options determine whether Siri offers voice feedback (as in, spoken responses - with this off, you just get written answers), and whether the Siri icon is displayed in the menu bar.

You also have the option of selecting which apps Siri can learn from, by clicking 'Siri Suggestions & Privacy'. Click 'About Siri & Privacy' to learn more about Apple's policy in this area. The short of it is much of Siri's learning is done on-device, and any information sent to Apple's servers is anonymised. However, if you're feeling a bit tin-foil hat, you can disable the learning checkboxes, at the likely expense of Siri being increasingly personalised as time goes on.

App Store

This pane determines the behaviour of apps you've installed from the Mac App Store. If you're not using an admin account, you'll need to click the lock to make any changes.

How to use System Preferences in macOS Sierra

Within the pane are six tickboxes. 'Automatically check for updates' does what it describes, and when active enables you to turn on or off the next four checkboxes. The first downloads newly available updates in the background (keep this on unless you're somewhere with a data cap, in which case temporarily disable it). The next three are for installing app updates, macOS updates, and system data files/security updates.

The other checkbox is for automatically downloading apps purchased on other Macs. This is useful if you use the same apps across a range of Macs, but again beware of bandwidth considerations and also storage if you happen to work with apps that take up a large amount of space.

At the foot of the window you'll see when the most recent check for updates was made, and a button to 'Check Now'. If the Mac knows updates are available, you'll get a 'Show Updates' button, which loads the Updates tab of the App Store app.

Note that if you're subscribed to the macOS beta program, you'll see a line stating your computer is set to receive updates. If you don't want beta updates to be shown, click Change and then the relevant button.

Date & Time

The Date & Time pane is where you adjust your clock, date and time zone. As of El Capitan, you need to add an admin password to edit its settings.

Under the Date & Time tab, you'll see a calendar and clock, above which is a checkbox. If the checkbox is ticked, your Mac's time and date will be set automatically, using the Apple server selected in the menu. If, for whatever reason, you want to override this (such as during a battery issue, which is causing your date to keep reseting), untick the checkbox and use the menus to change the time and date settings. A button at the bottom of the pane sends you to the Language & Region pane, for amending date and time formats across your system.

How to use System Preferences in macOS Sierra

Under Time Zone, you get a world map and an outline of your currently selected timezone. If the checkbox in this tab is selected, your timezone will be chosen automatically, based on your current location. Again, this can be overridden - untick the checkbox and then tap a point on the map. macOS will estimate the location. If you want to fine-tune it, you can type a place into the 'Closest City' field.

How to use System Preferences in macOS Sierra

Most of what you find in the Clock tab is for adding the date and time to the menu bar. Turn on the clock by ticking Show date and time in menu bar and use the radio buttons below to choose between digital and analogue options. The latter is quite small and therefore not especially clear when in the menu bar; when selected, it also greys out all subsequent menu-bar clock options.

The digital clock has more settings, enabling you to optionally display seconds, flash the time separators, and use a 24- or 12-hour clock. If you decide on a 12-hour clock, you can optionally show AM/PM indicators.

How to use System Preferences in macOS Sierra

You can also add the day and date to the digital clock, using the checkboxes to the right of Date options. The day is shown in abbreviated form - for example, 'Fri' for Friday; and the date is also abbreviated, to the likes of '17 Dec'. The final option is Announce the time, which is done hourly, half-hourly, or every 15 minutes. Using Customize Voice…, you choose a voice, speed and volume level for this feature.

Using Startup Disk on a Mac

Using Startup Disk, you can determine the disk used to startup your Mac. What 'disk' means in practice is a partition, drive or volume with a viable operating system installed. You can also use this pane to restart your Mac in Target Disk mode, which effectively turns it into an external drive that can be connected to another Mac, whereupon you can copy across data and perform diagnostics and disk repairs.

On opening the pane, your Mac will locate and display disks that are potential candidates for restarting from. You'll see the name of each disk, and the operating system installed; standard Macicons will differentiate between local and externally connected disks. In order to see any further information or make changes, you will need to unlock the pane with an admin password. Hold the cursor over any icon and you will also see the build number of the relevant operating system.

How to use System Preferences in macOS Sierra

In the displayed image, the Mac in question has an internal drive, and an old external back-up drive from an archive is connected, which has on it an older Mac operating system (be it a previous version of macOS or OS X). Depending on your set-up, you may see additional external drives, or partitions from your Mac's drive, each of which may have different versions of macOS or OS X installed. In any case, selecting one of these and clicking Restart will cause the Mac to attempt to startup from that disk.

Having started up from another disk, be mindful it's like using an entirely separate Mac. If you're using an old back-up/clone, Save dialogs will default to that disk and not your 'standard' one; additionally, systems on external drives may have significantly longer startup times than you're used to and be relatively sluggish to respond, due to the throughput speed from the hardware they're housed on. However, starting up from external disks can be useful. For example, you can use software or an old set-up that's no longer supported by the current version of macOS; alternatively, if your main disk dies and gets replaced, you can startup from a backup/clone and copy its contents back to your Mac.

Should you need to, it's also possible to change your startup disk during your Mac's boot process, rather than using the Startup Disk pane in System Preferences. To do so, hold the Option (Alt) key as soon as you turn on/restart. The Mac will scan for connected drives and present you with a list of options. Select one (use the cursor or left/right keys and Return) and the Mac will start from that disk.

The other option in the pane itself is clicking the Target Disk Mode button. Do so having connected your Mac to another via Thunderbolt or FireWire and it will, as previously noted, effectively become an external drive. If the Mac has a display, it will show the Thunderbolt or FireWire symbol. Target disk mode can also be triggered during startup/restarts by holding the T key.

Using Time Machine to back up a Mac

How to use System Preferences in macOS Sierra

Apple's Time Machine system is designed to safeguard your Mac's data by backing it up to an external disk. If you've not done anything with Time Machine to date, the System Preferences pane will be in its default state. To the left is a checkbox to determine whether Time Machine is used automatically. On the right is a button used to select a backup disk, some information about what Time Machine does, a checkbox that determines whether Time Machine is shown in the menu bar, and an Options button.

Turn Time Machine on and it will list suitable disks for use. Generally speaking, the location you're copying to should have more free space than the capacity of the disk you're intending to backup. If you're unsure what size disk your Mac has, go to the Apple menu, select About This Mac, and click Storage. An overview will be provided that outlines the size of your disk (and those connected).

For lots of related advice, read How to back up a Mac using Time Machine and How to transfer a Time Machine backup to a new Mac.

How to use System Preferences in macOS Sierra

Bear in mind that if the disk is partitioned and you only intend to backup the one partition, the external drive only has to be larger than that rather than the entire disk. (So, for example, if a Mac's 500 GB disk has been evenly split in two, the external drive would need to be larger than 250 GB, not 500 GB - although the more space you have, the more versions of documents and data Time Machine can store.)

How to use System Preferences in macOS Sierra

On selecting a disk, you can choose whether to encrypt your backups via the checkbox; clicking Use Disk then gets everything started. Back in the main Time Machine window, you'll see a countdown to the next backup, and details of the oldest and latest backups (which will start out as 'None').

When a backup is taking place, you'll see how much data is being backed up, how much is left to go, and approximately how long this will take. Your first backup will probably take quite a long time, but subsequent ones should be faster, since less data will be copied.

How to use System Preferences in macOS Sierra

Using Select Disk, you can update the disk used for backups, or even use multiple disks. With the Options button, you can exclude items from your backup. Click the '+' button and then select a document or folder. Its size will be listed, showing the impact on the entire backup.

Generally, there's not much point in omitting anything from backups, because that data will not be available if you later need to restore. The Options sheet also includes a checkbox so you can choose whether you are notified when old backups are deleted; on notebooks, there will also be a setting for whether Time Machine should backup while on battery power.

The final setting is the checkbox for showing Time Machine in the menu bar. The menu extra details the current backup, if one is active. In fact, the icon provides an at-a-glance view, once you know what to look for. When idle, it will be a block with a circular arrow around it, but when a backup is in progress, a second arrow is added; if an error occurs, the clock will become an alert icon.

How to use System Preferences in macOS Sierra

The menu also enables you to skip the current backup and to enter Time Machine. The latter won't be much use immediately, but access it once you've been running Time Machine for a while and you'll be able to access previous versions of Finder windows, select old versions of documents and then restore them.

Should a much bigger disaster befall your Mac, you can restore your entire Mac from a Time Machine backup. Hold Cmd+R during a restart, select Restore from Time Machine Backup, and click Continue. Select your backup disk and click Continue, and then the most recent backup, before clicking Continue again. The Mac will restore (which may take a while) and restart. The subsequent Time Machine backup may then be a full one.

Accessibility settings

Many Mac users never venture into the Accessibility pane in System Preferences, but although it's primarily designed to assist people with specific vision, hearing and motor requirements, plenty of the available options can be beneficial to a far wider range of users.

The pane is split in two. From the sidebar on the left, you select the section you wish to access. Sections are grouped into five distinct categories, to make finding everything simpler: General Vision, Media, Hearing, and Interacting. On clicking one of the sections, its options appear in the right-hand side of the pane.

General details the accessibility shortcut (Command+Option+F5) that brings up a system-wide window for turning on and off accessibility features. It also provides checkboxes for determining what features are listed in said window.

The window provides access to: enabling zoom; enabling VoiceOver; enabling Sticky Keys, Slow Keys and Mouse Keys from the Mouse & Keyboard settings; and Display's 'Invert display colours' checkbox. Buttons provide access to the Keyboard System Preferences pane ('Keyboard Shortcuts…') and Accessibility ('Preferences…'), while Done (or tapping Escape) closes the window.

The four sections within Vision are VoiceOver, Zoom, Display and Speech.

VoiceOver provides spoken/brailled descriptions of items on the screen. Turn on VoiceOver using Command+F5. A prompt will then provide the means to learn more (press Space) or skip the intro (V). Use VoiceOver and Turn Off VoiceOver buttons act as 'continue' and 'cancel', respectively, for the feature.

Zoom is a tool for zooming in and out of the display, thereby assisting people with certain vision problems. With Use keyboard shortcuts to zoom turned on, the listed shortcuts can be used to toggle zoom, zoom in, zoom out, and toggle smooth images. Use scroll gesture… instead has you work with a user-defined modifier key and mouse/trackpad gestures (for example Control and a two-finger vertical swipe) to zoom. Smooth images smooths visuals when zooming.

Zoom follows the keyboard focus ensures the zoom follows whatever you're doing with the keyboard. By way of example, turn this on and if you press Command+Tab, visual focus would move to the task switcher; but if this option was turned off and you happened to be zoomed into the top-left of the screen before pressing Command+Tab, you might not even see the switcher.

New to macOS High Sierra is Speak items under the pointer. This defaults to 'Only when zoomed' but can alternatively be set to work 'Always'. As you might expect, the feature has your Mac read aloud whatever's under the pointer when it stops (such as a back button), and you can adjust how long your Mac takes to speak by using the 'After delay' slider.

If you decide to use zooming, you should make time to explore Zoom Style, which provides the choice between the entire screen zooming in and out ('Fullscreen'), or just zooming a section within a window that follows the pointer rather like a floating magnifying glass ('Picture-in-pcture').

The More Options… button opens a sheet with settings for the chosen zoom style. When using Fullscreen, you get sliders for maximum and minimum zoom levels. Show preview rectangle when zoomed out places a black border on the screen, showing the portion you'll zoom into. The radio button group enables you to choose how and when the zoomed-in screen image will move: with the pointer, only when the pointer reaches the edge of the zoomed area, or so the pointer remains near the screen centre.

With Picture-in-picture, you get a magnification slider, options for the window's position - stationary, following the cursor, or tiled along the edge. The last of those splits the screen vertically. On the left, you get the magnified view, and the standard view remains on the right. Each scrolls independently. If you have a vestibular condition, be aware that this can be a motion/vertigo trigger (as, indeed, can some other aspects of zooming).

Cursor style provides the means to switch the standard pointer for a crosshair. The other options are for inverting the colours (specifically within the zoomed area), enabling zoom temporarily by holding the Control and Option keys, and speaking items under the mouse after a delay. With Adjust Size and Location, the area the tiled view takes up can be fine-tuned.

Display starts off with six checkboxes: 'Invert colors' (reverses all screen colours); 'Use grayscale' (uses only grey shades for everything on-screen); 'Differentiate without color' (adds shapes alongside - or instead of - colour, in order to convey status); 'Reduce Motion'; 'Increase contrast'; and 'Reduce transparency'.

Those last two options will be of particular interest if you've had problems since Yosemite's visual refresh. They're both designed to bring extra clarity to what you see on screen - Increase contrast darkens some colours, makes window controls more distinct, and removes transparency from window sidebars, toolbars and menus.

If that effect is a bit too fierce for you, instead just check Reduce transparency. Colours then remain unaffected, but system transparency effects will all disappear, resulting in solid menus and toolbars; this means in the likes of Maps, the actual maps won't affect the colour of the toolbar as you scroll the page.

Reduce Motion arrived with macOS Sierra and is, like on iOS, designed to reduce potentially dizzying animations peppered throughout the operating system. By example, the animations for entering and exiting full-screen, Launchpad and Mission Control are replaced by crossfades. Switching between full-screen apps and desktops also no longer animates by way of sliding, although pages in Launchpad do. Clearly, this is a feature on which Apple will build, and so if you use it and find issues, email [email protected] with your concerns.

Two sliders are found below the checkboxes. Display contrast is distinct from Increase contrast. It changes the contrast of all on-screen elements, in a manner similar to on a television or in a graphics package. Even a slight adjustment has a big effect; at maximum levels, OS X becomes essentially unusable. 'Cursor size' is more useful, increasing the size of the pointer. 'Normal' is the standard setting; 'Large' is even bigger than a standard Dock icon.

New to macOS, the Speech section is essentially a streamlined take on the Text to Speech tab of the now mothballed Dictation & Speech System Preferences pane.

Here, you choose settings for having your Mac read back text to you. Under the System Voice menu, choose a voice, or select Customize… to download a new voice.

Note that macOS has plenty of variants for some languages. For example, you can download male and female French voices, but there are separate Canadian French options. For English, there's a massive range to choose from, including voices with American, British, Australian and Indian accents. Be aware, though, that each download may take several hundred MB of space on your Mac's drive.

Back in the main pane, use the 'Speaking Rate' slider to determine the rate of speech and click the 'Play' button to preview. ('Normal' can be a bit tardy, but too fast can result in unintelligible output.)

Below, check Enable announcements if you want your Mac to speak alerts, and click Options to fine-tune. Within the sheet, you can choose the voice and phrase that begins said alerts (customising the latter, if you wish), and the delay before they are spoken.

The next checkbox, Speak selected text when key is pressed… allows you to create a shortcut for speaking selected text that can, broadly speaking, be used throughout macOS. Click Change Key… if you want to change this from the default, taking care not to pick a shortcut that may clash with others in applications you use. (Option/Alt + § is a good bet.)

In most applications, pressing the shortcut will result in your Mac speaking from the start of the current text field/document if nothing is already selected. Select a piece of text and only that will be read back. Press the shortcut a second time and your Mac will be silenced. The text-to-speech system is extremely handy for proofing text, since it's easy to miss errors when reading but they tend to stick out when spoken to you.

(Note that certain apps use non-standard windows and may only read the window title rather than the text. This is rare, and the only workaround is to copy text to a well-behaved app, have it read there, make your changes, and then copy it back again.)

In the Media category are two sections: Descriptions and Captions.

With Descriptions, you get a single checkbox, which plays video descriptions when they're available. In Captions, you define settings for closed captions and subtitles. Three styles exist initially: Default, Classic, and Large Text. You can create your own using the '+' button, whereupon you choose a name, background colour and opacity, text colour, font, and text size. In all cases, you can determine whether the video can override your choices when necessary. The checkbox at the bottom of the window when ticked will ensure closed captions/SDH are used rather than standard subtitles, when available.

The Hearing category has one section: Audio. This has two settings. The first adds a screen flash when an alert sound occurs, and this can be tested by clicking the 'Test Screen Flash' button. This has broader uses than just assisting people who are hard of hearing - if you're Mac's muted at night, it can be a great way of attracting your attention when an alert occurs. 'Play stereo audio as mono' adjusts all audio output to mono. This is particularly useful for users with poor hearing in only one ear when they're listening through headphones.

The Interaction category has five sections: Dictation, Keyboard, Mouse & Trackpad, Switch Control and Dwell Control.

Dictation provides further means to fine-tune dictation settings for your Mac. The single button, Dictation Commands…, opens a sheet that lists commands, categorised into Selection, Navigation, Editing, Formatting and System. Items can be enabled or disabled using the checkboxes, and selecting one displays accepted speech input in order to trigger the relevant command.

At the bottom of the sheet is a checkbox labelled Enable advanced commands. This adds new sections to the list: Application, Document and User. The last of those is designed for you to add custom commands. To do so, click the '+' button, and then input a term, select the app the command should work in (or use 'Any Application'), and then choose an action from a pre-defined list: Open File; Open App; Run Workflow; Paste Text; Paste Data; Keyboard Shortcut. Select a custom command and click '-' to delete it. Commands included by default cannot be removed.

In macOS High Sierra, there's now a Siri section. At present, this merely enables you to activate 'type to Siri' by clicking the checkbox. With this feature active, you type in your requests to Siri, rather than speaking them.

The Keyboard section is about helping anyone who may have difficulties typing and using keys. When Enable Sticky Keys is on, modifiers (Shift, Control, Command, Option) remain active, and their icons are displayed at the top-right of the screen. A sound also plays to denote the activation of one of these keys. Press the same modifier a second time and it's highlighted. Press a third time and it's cancelled. Modifiers also disappear when a keyboard shortcut is activated. (For example, press Shift and S and that triggers Save, thereby turning off the modifier.)

The Options… button provides further settings. You can toggle Sticky Keys by pressing Shift five times, turn off the audio alert, and change the screen corner in which the key icons appear.

Enable Slow Keys is all about adjusting the amount of time between when a key is pressed and when it's activated. Click Options… and you can toggle key sounds and adjust the acceptance delay. Having sounds on with Slow Keys is a good idea if you use an especially long delay, because it provides extra confirmation regarding key presses. This may not be necessary when typing, but it's useful when using keyboard shortcuts.

Mouse & Trackpad starts off with Enable Mouse Keys. When active, you can use an extended keyboard's number pad to control the pointer. On keyboards lacking a number pad, you use 'I' for the mouse button and the keys around it - 7, 8, 9; U, O; J, K, L - for directions. However, standard key usage is disabled while Mouse Keys is active, and so we recommend getting an extended keyboard when using this feature.

Click Options… and you can choose to press Option five times to toggle Mouse Keys, ignore the built-in trackpad when Mouse Keys is active, and define the delay and maximum speed. Those last two options need careful tuning to individual users. If the delay and speed is too slow, it will be frustrating to navigate using Mouse Keys; too fast, though, and the user may often miss their targets.

The rest of the pane is concerned with adjusting the behaviour of your mouse or trackpad. With Double-click speed, you can reduce the speed required for that action, thereby making it accessible to anyone who cannot click a button twice in succession quickly enough. Similarly, the spring-loading delay (for example, when dragging a document over a folder) can be adjusted to suit. A final checkbox, which isn't always displayed, is a setting for ignoring the built-in trackpad when a mouse or wireless trackpad is present.

At the foot of the pane, there are two buttons, providing quick access to, respectively, trackpad and mouse options. For trackpads, you can adjust the scrolling speed, set scrolling to be with or without inertia, and enable dragging without drag lock, with drag lock and as a three finger drag. For mice, you just get to change the scrolling speed.

Switch Control is explained in more detail on Apple's website, but is essentially all about performing actions simply by clicking a switch. Switches can be all kinds of devices; examples include a keyboard key, a mouse button, a joystick, or a specialised adaptive device.

The Switch Control options are divided into three tabs. General turns on Switch Control, which launches the Home row window. You press a switch (such as Space on your keyboard) to cycle through ('scan', in Apple's terminology) the options and then a second time to make a selection.

Depending on the selected option, subsequent selections will also be made by pressing the switch. (For example, select Menu Bar, and the selection will flick back and forth between the menu bar menus and menu extras; select the former and the system will scan through the menu titles and then, after another selection is made, items within that menu.)

Other options within General include the means to hide the panel after a period of inactivity, and to access the Panel Editor, designed to program a new switch or device into the system.

In the Switches tab, you can define and assign switch inputs using the '+', '-' and cog keys, and adjust the timing of switch usage. Under Navigation, there are further settings for changing how scanning operates. Another timing button is included here, but for navigation elements. Here, you can determine how rapidly scanning moves, and how long (if at all) the system pauses on the first item.

Dwell Control arrived with macOS Sierra but appears absent in High Sierra, and allows the mouse pointer to be controlled using head or eye-tracking technology. When enabled and the cursor remains stationary for the amount of time specified in the Settings tab, the defined action will be performed. (By default, this is three seconds for a left-click.) You can also set a zoom timer (two seconds, so the screen zooms in before a click).

Like Switch Control, Dwell Control when active offers an on-screen panel for easier access to key actions. A checkbox in the General tab enables you to hide this after a defined amount of time, and the Open Panel Editor button provides an editor for configuring the panel.

As a final note regarding Accessibility on Mac, some settings you're likely to want to have quick access to are available by way of an overlay window. Press Option+Command+F5 and you'll see 'Accessibility Options', and the rest of the screen will dim. The window provides access to: toggling how zoom is controlled (by keyboard shortcuts or scroll gestures); enabling VoiceOver; enabling Sticky Keys, Slow Keys and Mouse Keys from the Mouse & Keyboard settings; and Display's 'Invert display colours' checkbox and 'Adjust contrast' slider. Buttons provide access to the Keyboard System Preferences pane ('Keyboard Shortcuts…') and Accessibility ('Preferences…'), while Done (or tapping Escape) closes the window.