Apple is making major changes to iOS 12 software, including an iOS 11.2 update that will bring support for some new hardware.
Users of the iPhone 5S and 5C should upgrade to the latest software version.
Those on older devices should wait until the next software update to get the new features, but those upgrading to iOS 10.3 or higher should get the latest update as soon as possible.
The iPhone 6 and 6 Plus should get iOS 11 or higher.
Those running older versions of iOS will need to wait until November 29 to upgrade.
Apple will also roll out an update to its Mac app for iPhone and Mac.
The update should roll out to users soon.