The quality-of-service class for maintenance or cleanup tasks that you create.
- iOS 8.0+
- macOS 10.10+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
- Xcode 6.0.1+
Background tasks have the lowest priority of all tasks. Assign this class to tasks or dispatch queues that you use to perform work while your app is running in the background.
The quality-of-service class for user-interactive tasks, such as animations, event handling, or updating your app's user interface.
The quality-of-service class for tasks that prevent the user from actively using your app.
The quality-of-service class for tasks that the user does not track actively.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.Learn more about using Apple's beta software