The iPhone maker unveiled iOS 11 at its Worldwide Developers Conference earlier this year. The operating system, which runs on iPhone, iPad, and iPod Touch, comes with some design tweaks and improved support for augmented reality, a technology that overlays virtual objects on the real world. Apple’s iOS 11 also comes with camera improvements and a totally redesigned App Store that the company says, will do a better job of surfacing apps.

But before you can experience that, you need to get ready for iOS 11. And you probably should determine whether it’s really a good idea to download it.

Not All Devices Are Supported

First things first, you need to determine whether Apple’s iOS 11 supports the device you’re using. Chances are it does, but if you’re using a really old iPhoe or iPad, you might be in trouble.

Any iPhone from the iPhone 5s to now works with iOS 11. Those who are running the iPhone 5 or older, then, are out of luck.

On the iPad side, the company’s operating system will run on the iPad Mini 2 and newer, as well as the fifth-generation iPad, all iPad Air models, and all iPad Pro models.

Only the sixth-generation iPod Touch works with iOS 11.

Prepare Your iPhone and iPad

Before you download iOS 11, remember to backup your data. Apple has done a good job over the years of making it safe to upgrade to a new operating system without losing your data, but there’s always a chance your iPhone will turn on and all of your content is gone.

If you have an iCloud account, simply force Apple’s cloud service to back up your device by going to Settings > iCloud > Backup. In that panel, you’ll see an option to “Back Up Now.” You can also back up your device by connecting it to a computer.

Either way, wait for your iDevice to be fully backed up before you move forward.

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Is iOS 11 Free?

Yep. Apple doesn’t charge for iOS 11.

How Will Apple Deploy iOS 11?

Apple will offer iOS 11 through an “over-the-air update.” That means you’ll be alerted from your iPhone sometime today to a new software update. Just like all other software updates, you can choose to download iOS 11 from your iPhone, iPad, or iPod Touch, and Apple’s software will take it from there.

What Are Some of the Best Features?

It depends on what you’re looking for. But Apple’s iPad has arguably gotten the best update in iOS 11 and will get features you won’t find in the iPhone, including a new file-storage service and a wider dock so you can see more apps at the bottom of the screen. It’s also easier to use more than one app at the same time with iOS 11 for the iPad.

On the iPhone side, you’ll see some design tweaks and a streamlined Camera app. Apple’s Messages will make it easier to express yourself and the company’s Siri virtual personal assistant should be smarter. Apple Music is also getting a design overhaul.

The Early Adopter Problem

The big question: Should you download iOS 11 on the first day? After all, it’s possible that the software isn’t stable and therefore, could cause problems.

Ultimately, that’s a personal decision and it might be a good idea to stick with iOS 10 until you hear reports of how stable iOS 11 is.

However, Apple has been testing iOS 11 for months, and beta users around the world haven’t reported many problems. So iOS 11 should be rather stable at launch.

What If I Don’t Like iOS 11?

Go back to iOS 10!

Remember that backup you made before you downloaded iOS 11? Well, if you don’t like Apple’s new software, simply restore your iPhone to your old backup and your device will go back to the way it was before iOS 11 ever shipped.