Name the main components of an Android application.

Activity: Represents a single screen of the user interface. Manages the lifecycle.

Service: A component that performs operations in the background without providing a user interface. For example, playing music or downloading a file.

Broadcast Receiver: A component that reacts to system-wide broadcast announcements, such as an incoming call or low battery. Does not have a user interface.

Content Provider: Provides structured access to an application's data managed by the application, other applications (e.g., contacts, calendar).