(CBS) - Apple's iOS 8 is rolling out for users to download starting today. The updated operating system for iPhones and iPads has a number of new features. Here are some highlights of what to expect and how to prepare your device before downloading, from the experts at CNET:
Apple Pay
One of the most significant updates is the addition of Apple Pay, Apple's mobile payment system, which will work with the iPhone 6 or 6 Plus (as well as the Apple Watch when it's released next year).
Notifications
iOS 8 has a new notification system "so you can respond to events, reply to messages and interact with alerts right from the lock screen and drop-down menu," CNET's Bridget Carey explains.
Shortcuts
Double tapping the home button will provide shortcuts to contact the people you have spoken to recently. Icons of their faces will appear across the top of the screen, and you can just tap their face to call or message them.
Siri
You'll be able to operate Siri hands-free, by voice command, as long as your device is plugged in.
Home and health
The new system includes HomeKit - a framework for controlling Internet-connected gadgets in your home - and Apple's Health app for fitness tracking.
The keyboard
A feature called QuickType will offer word suggestions as you type. "The keyboard is more adaptive to the way you talk, and you can send audio clips and maps of your location as messages to friends," Carey said. iOS 8 will also allow you to download third-party keyboard software for additional options.
Photo editing
iOS 8 also offers new photo-editing tools, including auto-straightening, cropping and color correction. Edits to photos will appear across all your Apple devices. Check with CNET for a detailed walk-through of how to use the new photo features after iOS 8 comes out.
iCloud Drive
iCloud Drive allows you to browse, edit, and share files across different Apple devices, similar to cloud services like Dropbox and Google Drive. However, it will not sync up with your Mac until Apple rolls out its OS X Yosemite operating system update later this fall, so users may want to wait until then to opt into iCloud Drive.
Is iOS 8 for everyone?
If you have an older Apple product such as the iPhone 4S or iPad 2, you may want to skip the upgrade, CNET advises. Last year, some owners of older iPhones experienced performance issues with the iOS 7 upgrade.
Before you download
Here are steps you may want to take to prepare your iPhone or iPad for iOS 8:
1. Make some space for the new software, advises Carey. You will need about 3 gigs of free space to upgrade. Start by deleting apps you don't use and transfer some of your photos to your main computer or a cloud service.
2. Back up your data in case there are any issues during the update.
3. Check your Facebook settings for outside apps. "You may be surprised to see how many apps connect with your Facebook account - and for security, you'll want to delete apps that you don't use anymore," Carey said.
CNET has more information on iOS 8 and details on what to expect from the new operating system.
