The service type associated with this request.
- iOS 4.0+
- macOS 10.7+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 8.0+
The network service type provides a hint to the operating system about what the underlying traffic is used for. This hint enhances the system's ability to prioritize traffic, determine how quickly it needs to wake up the cellular or Wi-Fi radio, and so on. It improves the system’s ability to optimally balance battery life, performance, and other considerations.
For example, specify the
NSURLRequest service type if your app is performing a download that wasn’t requested by the user—like prefetching content so that it’s available when the user chooses to view it. By contrast, continually connected voice and video apps should use the
video service types, as appropriate.