What is "android-service"

An Android service is a component for performing operations, usually long, without user interaction. Has a life cycle independent of that of the component that started it and by default (default) runs on main thread of the host process.

A service can take two forms:.

• "Started" if initiated by the method startService().
• "bound" when initiated by the method bindService().

How a service can be started depends on which methods were rewritten: onStartCommand(), onBind() or both (in this case the service may take both forms)

Regardless of how it is started, any component can use the service, even from a different application.

In the same way as a Activity, a service must also be declared in the Androidmanifesr.xml

Official documentation.