Apple's macOS Catalina arrives today, October 7. This free upgrade lets you use your iPad as a second display, draw with an Apple Pencil in Mac apps, and run more iPad apps on your Mac.

Catalina is compatible with most Mac models released after 2012. If yours ran macOS 10.14 Mojave, it will almost certainly run Catalina.

Dropping Support for 32-Bit Apps

The 32-bit app warning message on macOS Mojave.

Apple has warned for years that 32-bit app support is going away, and this will happen when macOS Catalina arrives. Most apps should be updated by now, but if you have an older Mac app that shows you the "[App] is not optimized for your Mac and needs to be updated" message when you launch it, that app won't work at all in Catalina.

If an app you need occasionally displays this message when you launch it, don't upgrade to Catalina until there's a newer version of that app, or you find a replacement for it.

Related: How to Check Your Mac for 32-Bit Applications That Will Stop Working After High Sierra

Music, TV, and Podcasts Get Separate Apps

Apple Music app in macOS Catalina

Mac users have been begging Apple to break up iTunes for years, and in macOS Catalina, this finally becomes a reality. There are three new apps to handle media: Music, TV, and Podcasts. The Music app is where you go to stream Apple Music, manage your library, and purchase tracks from the iTunes Store.

The TV app is the new home of all things video. Here, you find all the TV and Movies you've purchased from iTunes, plus the iTunes Store to download even more. This is also where you stream content from Apple's new TV+ subscription service when it finally launches this fall.

The Podcasts app is nothing groundbreaking, but it's nice to finally be able to manage subscriptions, download episodes, and discover new shows outside of iTunes. All three apps use a very similar interface. And they're noticeably leaner and more responsive than their previous iTunes implementations.

If you miss iTunes, don't worry---on Windows, the classic iTunes app will live on.

Use Your iPad as a Second Display

Use iPad as Second Display with Sidecar in macOS Catalina
Apple

With the new feature called Sidecar, you can turn your iPad into a second display. It works with any iPad that supports the Apple Pencil, although Apple hasn't announced which Mac models are officially compatible. From what we've heard, Sidecar should work on Macs released in 2016 or later.

You can already do this if you use a third-party app, like Duet Display, but now it's available in macOS and iPadOS.

To enable Sidecar after you upgrade your iPad to iPadOS 13 and your Mac to macOS Catalina, head to System Preferences > Sidecar, and then select your device from the drop-down menu. You can also enable a sidebar to access keyboard shortcuts, and a touch bar at the bottom of the screen just like the one on a MacBook Pro.

Use Your Apple Pencil in macOS

Use Apple Pencil in macOS Catalina with Sidecar
Apple

When you connect your iPad to your Mac via Sidecar, you can take full advantage of your Apple Pencil using the touch display. You can draw in apps, like Illustrator, touch up photos in Affinity Photo, or use Preview to mark PDFs or sign your name.

However, note the small print on Apple's website that says some apps will need updates to work with Sidecar in this manner.

Run iPad Apps on Your Mac

Sticking with the iPad theme, macOS Catalina also makes it easier for iOS developers to port iPad apps to the desktop. Apple calls this Catalyst, and we should see an influx of apps coming to the Mac over the next few months as developers familiarize themselves with the porting process.

Catalyst is the official name for Project Marzipan, which debuted at Apple's 2018 Worldwide Developers Conference (WWDC). When Apple released macOS Mojave, it included a handful of apps based on this technology, including News and Voice Memos. Catalyst puts it in the hands of third-party developers.

Apple used the racing game Asphalt 9 to demonstrate the feature when they announced Catalina. The presentation noted how the mobile-optimized game takes advantage of an even more powerful desktop machine to hit higher resolutions and deliver more impressive visual effects.

It's not just games that will be ported across, though. Apple also highlighted iOS apps, like Twitter, TripIt, and Morpholio. Expect to see more apps on the Mac as developers who had previously targeted iOS find it easier than ever to create Mac versions.

Screen Time Comes to the Mac

Screen Time for macOS Catalina

Screen Time---introduced on the iPhone and iPad with iOS 12 to help users monitor their device usage---is now coming to the Mac. It's likely the feature will be even more useful on the Mac because it helps you monitor which apps and websites you use throughout the day to improve your productivity.

You see your app usage, incoming notifications, and device pickups (including iOS devices). You can set limits, like how long an app can be used, or whitelist apps that are "always allowed." You can also restrict content, stores, and more. Screen Time on the Mac shares data across devices, so you can see your combined usage on one screen.

Screen Time also replaces the old Parental Controls panel in System Preferences. So, this is now where you set up parental controls on your Mac. It's more powerful and makes it easy to set limits based on real-world usage. If you've used Screen Time on an iPhone or iPad, the process will be familiar to you.

The Usual Security Enhancements

Security and Privacy Settings in macOS Catalina

Every macOS update includes a sprinkling of security enhancements and more fixes behind the scenes. Catalina introduces an iOS mainstay called Activation Lock for Macs with Apple's security-focused T2 chip. This works the same as it does on iOS, and prevents a thief from using your Mac even if it's been erased.

With Catalina, macOS now runs in a read-only volume. This prevents third-party apps from writing to the most sensitive parts of your system. This is another way Apple is trying to protect the core operating system; it also added to features, like System Integrity Protection and GateKeeper.

Catalina builds on the iOS-like permissions system introduced with Mojave. You now have more control over what apps can do on your system. Apps have to ask to record your screen or typing, just as they do for your webcam or microphone. You'll find the new options under System Preferences > Security & Privacy > Privacy.

Approve macOS Actions on Apple Watch

You can now approve admin-level changes, like installing a new app or making changes to root files, on your Apple Watch without having to type your password.

The feature works with any Mac and Apple Watch combination that can already take advantage of the Auto Unlock feature. You need a mid-2013 Mac and an Apple Watch that run macOS Catalina and WatchOS 3 or later, respectively.

Some Old Apps Get an Overhaul

macOS Catalina Photos app

As is customary in each macOS release, a handful of first-party apps are getting the following improvements:

  • Photos: It gets a new look that matches iOS 13. It's also easier to browse your library by day, month, or year. And it's now smarter at identifying "moments," like trips abroad and celebrations.
  • Reminders: This app was rebuilt from the ground up and mirrors iOS 13. You can now add attachments, tag people, and browse your reminders via Smart Lists, with labels like, "Today" and "Flagged."
  • Notes: A new gallery view makes it easier to browse content, and the search is more powerful. You can now share entire folders of notes and collaborate with others on iCloud. Plus, there are bulleted lists and easy drag-and-drop reorganization options.
  • Safari: The browser received its usual yearly updates to improve rendering performance and web standards. There's also a new start page, complete with Siri Suggestions for context-relevant shortcuts to bookmarks, iCloud tabs, and links from Reading List and Messages.
  • QuickTime Player: A brand-new picture-in-picture mode is just one of the upgrades for this app. It also now features a movie inspector pane that shows you more technical information about the current file. You can also create a movie from a sequentially-numbered folder of images in H.264, HEVC, or ProRes formats.

The New "Find My" App

The new Find My app brings together all the features of Find My Friends and Find My iPhone under one umbrella. Now, you can find all your friends and devices on the same map, and manage your location-sharing permissions, too.

Voice Control for Mac and New Accessibility Options

New Accessibility Features in macOS Catalina

Apple's speak-aloud accessibility feature, Voice Control, finally comes to Mac. It allows you to navigate your Mac with your voice. Speech recognition and dictation were improved, as were accessibility features, like numbered labels and grid-based selection. This means you can select, zoom, or drag files via voice commands.

Another enhancement called, "Zoom Display," allows you to keep a secondary display zoomed in at all times. And the "Hover Text" option displays highlighted text in high-resolution when you tap the Command key.

System Preferences Is More iOS-Like

System Preferences in macOS Catalina

System Preferences finally got a face-lift! When you launch it in macOS Catalina, you see your name at the top, just as you do on iOS. This new layout makes it easier to access account-related settings, subscriptions, and purchases, and manage all of your devices from a single interface.

Can Your Mac Run macOS Catalina?

If your Mac runs macOS Mojave, it should be able to run Catalina. According to Apple, the following models are compatible:

  • MacBook Air: 11- and 13-inch; mid-2012 or later
  • MacBook: Retina and 12-inch; early 2015 or later
  • MacBook Pro: 13- and 15-inch; mid-2012 or later
  • iMac: 21.5- and 27-inch; late 2012 or later
  • iMac Pro: 2017 or later
  • Mac mini: Late 2012 or later
  • Mac Pro: Late 2013 or later

To find your Mac's model and year, click the Apple logo in the top-left corner, and then select "About My Mac."

How to Install macOS Catalina

As usual, macOS Catalina is available as a free download in the Mac App Store. But remember, not all software will be compatible with it from the outset. If you rely on a particular piece of software, make sure it's compatible with Catalina before you upgrade.

After you confirm your Mac is compatible, back up your computer just in case anything goes wrong during the installation process. To do this, connect an external drive, launch the Time Machine app, and then follow the onscreen instructions.

After you back up your machine, launch the Mac App Store---macOS Catalina should be listed on the Featured tab. If not, just type "Catalina" in the App Store's search bar and search for it.

The installation file will download and give you an application called "Install macOS Catalina." Run it and follow the prompts to upgrade your Mac to the latest version of macOS.