This year's update to OS X has been officially previewed, and we know its California place name: Yosemite. But while developers have access to an early version of the new OS now, regular users will have to wait until the fall to use it (unless they sign up for, and get into, the public beta program). So there are lots of questions swirling around out there about OS X Yosemite; based on what we've learned at WWDC (and from testing out the early OS on a system that Apple loaned to Macworld's Jason Snell), here are answers to some of the most common.

The interface

What's this I hear about a revamped user interface?

You've heard correctly. Taking a cue from iOS 7, Yosemite now features transparency not only on the menu bar, but applied to windows and other small interface features, as well.

You'll also find that Apple has dispensed with the 3D design elements of old in lieu of flatter, more colorful surfaces. Toolbars have also been simplified. For example, in Safari, the Favorites bar no longer appears by default; instead, you find Favorites when you click in a window's smart-search field. Yosemite also uses a new System font, Helvetica Neue.

But why? I hate the translucent menu bar!

You aren't alone. Lots of people have been hating on the translucent menu bar since its initial debut back in OS X 10.5 Leopard. But that vocal minority doesn't seem to have swayed Apple. You will still be able switch off the translucent menu bar, though.

Is there any way to turn off window translucency, the way you can turn off menu-bar translucency?

As in iOS 8, you will be able to greatly reduce the transparency by visiting System Preferences > Accessibility > Display > Reduce Transparency.

How weird is Helvetica Neue as the system font?

It's initially a bit of a shock if you're used to Mavericks and older versions of OS X. But once that shock wears off, the font is fine, and it certainly matches the overall visual of Yosemite better than Mavericks's Lucida Grande would have. On a Retina display, the thinner font especially shines.

The Dock looks strangely new-but-familiar. What's up with that?

Back in OS X 10.4, the Dock was two-dimensional: a translucent background that separated app icons from the desktop. Starting in OS X 10.5, however, Apple changed the Dock's bottom position to render in 3D (unless you performed a Terminal tweak. With Yosemite's new flat UI, the Dock is back to being 2D again. We like it a lot from what we've seen so far, and it otherwise behaves just like the Dock we're used to: You will be able to resize and reposition it, hide it, and so on.

I've heard Apple changed the 'stoplight' buttons at the upper left of windows. Are they vertical again?

No, still horizontal, but in many windows they're now integrated into the toolbar, rather than above it, thus saving some screen real estate. They also have the same flatter appearance as the rest of the operating system. If you're a long-time Mac user, the experience will be a bit odd at first, but it should be a nice change--especially given the widescreen aspect ratio of all of Apple's current displays.

In addition, Apple has tweaked the behavior of the green button. Previously, it's always been a zoom toggle--though exactly how it zoomed varied widely. In Yosemite, the green button is now a full-screen toggle: individual windows zoom to the width of the screen when pressed, while the main window of an app enters full-screen mode. Many of us will miss the green button's zoom control, but given Apple's current emphasis on full-screen mode, this change makes a lot of sense and reduces clutter in the toolbar.

Are full-screen apps dead? I don't see the little double-arrow icon in the top right of windows.

Full-screen mode is alive and well. But as we just mentioned, Apple has done away with that specialized double-arrow button and instead changed the functionality of the green 'stoplight' button. The Full Screen keyboard shortcut (Command-Control-F) still exists and works within supported apps (Safari, Mail, and Calendar, for example). When you hold down the option key, the green button will turn back into its more familiar function of expanding the dimensions of your window.

What's this new Dark mode they mentioned in the keynote? How does it look?

The preview version of Yosemite we've seen doesn't currently offer Dark mode; chances are it'll appear in future betas. As you say, Apple did preview it on stage at the keynote: it appears to darken the menu bar and associated menus, with light text on a dark background.

How much does Yosemite resemble iOS? Does it still feel like prior versions of OS X?

While Yosemite does, as we mentioned above, pick up some visual effects--the translucency, brighter colors, flatter icons, and typography--from iOS 7, it does so in a way that feels very much like an evolution of OS X, rather than simply aping iOS. There are some options in programs such as Safari (the Favorites bar, for instance) that are hidden by default, but they can be easily accessed by power users. And as we noted earlier, if you really dislike translucency, you will be able to turn it off.

System Services

What's changed in Spotlight?

Apple has enabled Spotlight to tap into more information sources and expanded what you'll see in results lists. In addition to the files, apps, contacts, Messages, and other data Spotlight could already find, those sources now include Wikipedia; Bing; Maps; news; movie listings; and the iTunes, Mac App, and iBooks Stores. The Spotlight key command remains Command-Spacebar; if you conduct a normal Finder search by pressing Command-F, online sources won't be searched, just as they weren't in previous versions of the Mac OS.

Spotlight is also now more interactive. Not only will you be able to read a document within a Spotlight preview, but you'll be able to do things like send an email message, make a phone call, or get directions right from the search interface.

Will you be able to have more than one instance of Spotlight search?

Nope, it's just the one search bar. You may, however, see certain Spotlight search results when typing in a Safari window.

What are the chances I'll replace my third-party launcher with Spotlight?

We've been asking this question since Spotlight was introduced, and the answer seems to be the same: Spotlight improvements should make regular users happy; it's even better for quick local queries and for Siri-esque questions about movie showtimes. But more advanced users who rely on third-party launchers to do all sorts of productivity-boosting things will probably want to stick with those tools.

What does System Preferences look like now?

Other than new icons and fonts, it looks very much the same. The only new entry is Extensions: That's where you will enable and disable the extensions that appear in the Services and Share menus and widgets for the Today view within Notifications.

So, with the introduction of extensions and widgets, has Dashboard finally been killed off?

Surprisingly, no! Dashboard remains, but it's switched off by default. You will still enable it within the Mission Control system preference pane. It also exists as a separate app, found in the Applications folder, as always. But Apple is strongly advising developers who still rely on Dashboard to vacate the premises immediately. We'd be surprised if Dashboard survives past this release.

What's changed in Notification Center?

Third-party widgets are the big news in Notification Center. They allow developers to create little code snippets that display things like the current weather, sports scores, bidding in online auctions, and more. In addition, Notification Center takes a page from iOS and brings over the Today view, which provides a summary of your day's events, reminders, and birthdays, along with calendar events for tomorrow.

iCloud and connectivity

How is OS X more closely connected to my iOS devices? Why would I want that?

There are a couple ways in which your Mac and iOS devices will soon work together under Yosemite and iOS 8. These new capabilities center around iCloud Drive and a cluster of features Apple is calling Continuity: The first offers you a big Dropbox-like storage locker for all your app documents and projects; the second provides an integrated framework for you to access a variety of services seamlessly as you move between Macs and your iOS devices. As implemented in OS X Yosemite, those services fall into five distinct categories: Phone, SMS, Handoff, Instant Hotspot, and AirDrop.

What does the Phone part of Continuity do?

Think of your Mac as a big speakerphone and dialer for your phone. If your phone is within Bluetooth range of your Mac, you'll see caller ID information on your Mac's screen whenever your phone receives a call. You'll be able to accept or decline the call right from your computer, and if you answer, to talk and listen through your Mac. You'll also be able to initiate calls from your Mac by clicking on a phone number in Contacts; on a webpage; or in an email or text message.

What about SMS support?

This is pretty cool: If you have an iPhone and upgrade to iOS 8, you'll be able to push SMS messages--those "green bubble" messages from buddies who don't use an iPhone to text--to your Mac or other iOS devices, so that you can write and reply to them on any device you choose. You'll even be able to initiate SMS messages on the Mac.

And Handoff? What's that?

Most of us own more than one Apple device these days. While iCloud already helps us keep some information in sync between those devices, the process of switching back and forth between them is still often rough. Handoff aims to help smooth that out: If you start writing an email on your iPhone, you'll be able to pick up your composition on your Mac from wherever you left off. In the middle of reading an interesting article on your iPad when you need to head out the door? You'll be able to open up your iPhone and keep reading, right from the same scroll position.

Third-party developers can also take advantage of Handoff. Apple is providing a framework for developers who want to have their apps talk to each other on iOS and the Mac. Obviously we'll have to wait to see what kind of clever uses for Handoff those developers come up with.

Okay, and Instant Hotspot?

Currently, if your cellular carrier supports your iPhone's hotspot feature, you can configure your iPhone to create an ad-hoc wireless connection to your Mac, letting it use your phone's data plan for Internet access. Under Yosemite, however, whenever your iPhone is within Bluetooth range of your Mac, the phone automatically appears (along with its signal strength and battery level) in OS X's systemwide Wi-Fi menu. If you choose your phone from this menu, it automatically sets up a secure Wi-Fi hotspot and your Mac connects to it--no other action required. And your Mac automatically disconnects when it's not actively accessing the network to preserve the phone's battery life.

What about AirDrop? Don't I already have that on my Mac?

You do, but now it's even better: AirDrop now works between iOS devices and Macs, meaning you'll be able to exchange files on an ad hoc basis between the two, without the need for an Internet connection or even being on the same local network. Need to get a photo to your Mac from your iPhone? Fire up AirDrop. Want to send that PDF from your Mac to your iPad? Same thing. And you'll also be able to limit your sharing so that only your iCloud contacts can see your share requests.

So tell me about iCloud Drive. Is it really like a Dropbox folder?

Sort of: Starting with OS X Yosemite and iOS 8, you'll have access to an iCloud folder on both. That folder syncs with your other Macs and iOS devices (presumably running either Yosemite or iOS 8). If you drag and drop files into it, they will then appear on your other devices.

It looks as though some preliminary support for selective sync may exist, via System Preferences > iCloud > Documents & Data Options. But iCloud Drive doesn't yet appear to have the same robust sync options as Dropbox, nor does it appear to support sharing public links to files or folders. This may change as the system gets closer to release, however.

How much space will I get with iCloud Drive?

5GB for free, but in the fall you should be able to purchase 20GB more for just $1/month or 200GB for $4/month. Apple has even said that it plans to offer plans with up to 1TB of storage--good thing, considering that your iCloud storage limit includes your backups, photos, and documents.

Apps

What's new in Safari?

Following in the footsteps of the Finder redesign, Safari windows have been simplified. By default you will see just a couple of navigation controls, a button for showing or hiding the sidebar, the smart-search field, and Share and Tab View buttons. Also by default, when you click in the smart-search field, your favorites--represented as icons--will appear; just click on one of these icons and the associated site opens. The smart-search field doesn't show an entire URL by default, just the address of the server (say, macworld.com) you're connected to. And the title of the page isn't shown at all, unless you have multiple tabs open.

Browser tabs have changed as well. Although you'll still be able to see multiple tabs in a tab bar, when you click the new Tab View button in the top right corner of the toolbar, you'll see thumbnail previews of all your tabs in the main window. If you have multiple pages from a single site, they'll be stacked within this view. Below these thumbnails are iCloud Tabs--the ones that are open on other devices associated with your Apple ID. Click a preview or one of these iCloud Tab links and the page will open in Safari.

We mentioned improvements to Spotlight earlier and Safari is adding some of those same sources within its smart-search field. In addition, you'll have the option to choose DuckDuckGo as the default search engine. (Among other things, DuckDuckGo provides greater privacy than some other search engines.)

Apple claims that this new version of Safari is more responsive thanks to JavaScript engine optimization, as well as more energy efficient. It will support HTML5 Premium Video--a digital rights management system that allows protected-video playback in Web browsers. (For example, Netflix movies will play without any third-party plugin.) It will also come with support for WebGL, a JavaScript API for rendering 3D graphics in a browser.

Yosemite's Safari additionally offers an advanced Private Browsing mode (in which your browsing actions aren't tracked or saved). With today's Safari, when you switch on Private Browsing it applies to all open Safari windows. With the next version of Safari, you'll be able to create a window and devote it--and all the tabs within it--to private browsing. As with Safari on iOS devices, the color of the browser window will change to help you identify private windows. You'll be able to maintain separate windows that aren't configured to be private.

Has Apple removed the 'Reader' feature in Safari?

No! Reader and Reading List are still alive and well in the OS X Yosemite version of Safari; they've just been simplified. The Reader icon is now to the left of the search field, and is presented as a series of horizontal lines. Hover over that field, and you'll see a plus button to the right of the Reader icon; clicking that will send the webpage in question to your Reading List.

Any changes to the Safari sidebar Apple added in Mavericks?

Nothing major: the sidebar still houses Shared Links (links posted by people you follow on social networks), Reading List items, and bookmarks. A big upgrade to Shared Links is the ability to subscribe to individual websites--this is actually the return of RSS feeds to Safari. When you visit a site, if you click the Share button (in the upper right corner of a Safari window), on many sites you'll see a new Subscribe in Shared Links option. This essentially adds the contents of that site's RSS feed to your Shared Links list. For hard-core RSS users, this will probably not be useful. But more casual users might find Shared Links to be a good place to find new items to read, including items from favorite sites. We'll see.

What's new in Mail?

The two major new features are Markup and Mail Drop. If you've had occasion to annotate images in Preview, you'll get the gist of the way Markup works: When you add an image to an email message, you'll be able to invoke annotation tools to mark it up. These tools are remarkably similar to those you find in Preview: you'll be able to add shapes, arrows, and text and to fill out and sign PDF documents either by drawing in your signature or using one you've captured with a webcam.

Mail Drop is a method for sending really huge attachments (which can't make it through some email gateways). The service ties into your iCloud account and is confined to the Mail app. It works this way: If an attachment is too large, it'll be uploaded to your iCloud account and a link to the file will be sent to the recipient. If the recipient is also using Mail under Yosemite, they'll see that attachment just as they would any other. Otherwise, they'll receive a link to the attachment instead. When they click that link, the attachment will download. Although attachments sent via Mail Drop can be very large, they still can't exceed 5GB per message.

What's new in Messages?

There are a couple new exciting features coming to Messages in OS X. First is the app's new tap-to-talk feature, which will let you send quick voice memos to friends and family members. Like messages in apps such as Snapchat, those snippets will be temporary and disappear within a few minutes of being read unless you choose to save them. You'll also be able to send a quick video or multiple images.

Group texting is also getting a huge overhaul. You'll be able to name group conversations (for easier reference), add and subtract users to the conversation on the fly, and leave the conversation (or hit the Do Not Disturb button) if you're getting flooded with texts. Messages also makes browsing images and video in a thread much simpler; tapping the Details button will let you see any attachments you've saved in that conversation over time.

And, as we mentioned above, you'll be able to view SMS messages from your pals if you also have an iPhone.

I know they didn't mention Game Center... is the green felt still around?

A moment of silence for green felt: Game Center on OS X now uses the same colorful bubbles that first appeared in iOS 7. You'll also find the same categories as its iOS counterpart, including challenges and turns.

We didn't hear anything about iTunes, but I noticed that there was a new icon in the dock...

iTunes does indeed have a new icon in Apple's promo materials, but we've not actually seen the new version in the flesh. Stay tuned: if Apple follows its usual patterns, we may hear more about its music offerings in the fall, including what's behind that red icon.

What about Photos on the Mac?

OS X Yosemite won't ship with a Mac version of the Photos app, but Apple did preview an early version of the program that should show up in 2015. It features many of the same improvements and user interface found in the iOS 8 version of Photos, and it sounds like it will use the iCloud storage locker to upload full-resolution copies of your images and video.

Having all those images at hand might make you nervous about ever finding anything again, but luckily, Apple is adding a smart-search feature and a Favorites button. The search field will initially prompt you with a collection of nearby photos, images taken at the same time last year (for the nostalgia factor), and all-time favorites; but you'll also be able to search by date or time, location, or album name.

There are new editing features for images, too: Download an image to your device, and you'll be able to use a bevy of iPhoto-inspired features to crop, straighten, remove red eye, adjust lighting and contrast, and more. All of those edits sync across your devices, so that the fixed image appears in your library immediately. They're also non-destructive: if you decide you preferred your image unfiltered, you'll be able to revert it.

On top of that, OS X's Extensions for developers means that your favorite third-party apps could provide filters and adjustments that you could use from within the Photos app.

What does that mean for iPhoto? It's a good question. For many users, it might replace iPhoto entirely. It remains to be seen if Apple will reposition or refocus iPhoto for a different audience, or if iPhoto will soon join Dashboard on the list of Mac technologies we shouldn't get too attached to.