What's the best way to manage user accounts on a Mac?
If you share your Mac with other people in your household or office, you'll want to set up separate user accounts for each person. Each user can have different settings for things like the way their desktop looks and which tools or apps open at launch. Crucially, the admin user can specify which users can access specific files and folders. The admin can also set Parental Controls for other users. There's one 'special user' - Guest. By default, recent versions of OS X and macOS have the Guest user enabled. This allows a friend or colleague to use your Mac without having their own account or using someone else’s account. They can do all the things a regular user can do, but when they log out, all of the files and folders they’ve created during a session are deleted.
Groups are collections of users who have the same permissions to access files and folders.
You create and manage users and groups in the Users & Groups pane in System Preferences. Permissions for access to files and folders are granted in the Finder - more of that later.
When you set up your Mac for the first time, you'll have created an admin user, probably yourself. Launch System Preferences and click on Users & Groups. You'll see the account of the current user, you, at the top of the list on the lefthand side of the window. Click on the account and in the right hand window, you'll see some of the available settings. To make changes, you'll need to click the padlock at the bottom left of the window and type in your password. You can now change your password, by clicking Change Password, change your log in picture by clicking on it, or change which items launch when you log in, by clicking Login Items and clicking the + or - buttons at the bottom left of the next window.
How to set up and manage user accounts on a Mac: Add a new user
To add a new user, click on the + at the bottom left of the main Users & Groups window. The dropdown menu at the top of the next window allows you to choose what kind of user to create. Besides administrator and guest, there are three other type of user. They are described here.
Once you've chosen the type of user you want to create, type in the user's full name and a name for their account. Choose between using the user’s iCloud password and creating a new one, and type the password into the boxes. Now click Create User.
To create a group, choose Group from the New Account menu and give the group a name. In the next window, check the users you want to include in the group.
How to set up and manage user accounts on a Mac: Set Parental Controls
To enable Parental Controls for a user, click on that user in the lefthand window of Users & Groups and click the checkbox next to Enable Parental Controls. Now click Open Parental Controls. When the window opens, click through the tabs one by one and choose the options you want in each one.
So, for example, if you want to put limits on the times a user can use your Mac, click the Time tab and then click Weekday or Weekend time limits and set the limits. You can also specify times during which the user can't use the Mac. Other controls include the ability to restrict websites, prevent access to the user's private data by specific applications, and the option to specify which applications the user can run.
How to set up and manage user accounts on a Mac: Set files and permissions
If you store files on your Mac's internal storage, you should put them in a folder inside your Home folder. By default, a Home folder can only be accessed by the user in whose account it sits. The exception is the Public folder - any other user can read files in the main Public folder. Within the Public folder there's a Drop Box (not to be confused with Dropbox), into which any other user can write files.
To change the permissions of other folders or files in an account, or to set permissions for files or folders on external storage devices, click on the file or folder in the Finder and press Command-I to Get Info.
At the bottom of the window, click the arrow next to Sharing & Permissions. You'll see a list of users who have permission to read or write that file. To change the permissions for a listed user or group of users, click in the Privilege column opposite the name of the user or group and select and option from the menu. To add a new user or group, click the + at the bottom of the window and choose a user or group from the menu. Then click on the Privilege column to specify their permissions.
You might also have to give new users shared access to folders. To do that, go to the Sharing pane in System Preferences, click the checkbox next to File Sharing, drag the folder into the box under 'Shared Folders' and click the + under the list of users to add the new user. Now click in the privileges column next to the user to set their permissions.
How to set up and manage user accounts on a Mac: Set a Master password
A Master password allows an administrator to reset the password of another user if they forget it. To set one, click on the cog at the bottom of the left hand pane in the main Users & Groups window and click on Set Master Password. Type in the new password and verify it. You can now use this to reset the password of any user.
How to set up and manage user accounts on a Mac: Set login options
In the lefthand pane of the main Users & Groups preferences panes, click on Login Options. You can now specify whether or not a user is automatically logged in when your Mac restarts, by selecting the user from the dropdown menu next to 'Automatic login'.
The rest of the options in that window allow you to specify how the login window looks and how the fast user switching menu is labelled.