Android application components are the essential building blocks of an Android app. Each component is a different point through which the system can enter your app.
There are four different types of android application components. Each type of android app component serves a distinct purpose and has a distinct lifecycle that defines how the component is created and destroyed.
An activity is implemented as a subclass of Activity.
A service is implemented as a subclass of
A content provider is implemented as a subclass of ContentProvider
A broadcast receiver is implemented as a subclass of BroadcastReceiver
An Intent is an abstract description of an operation to be performed. Intent object, defines a message to activate either a specific component or a specific type of component. Intent if define a message to activate a specific component then it is called Explicit Intent. When Intent define a message to activate a specific type of component then it is called Implicit Intent.
There are separate methods for activating each type of component:
As you can see 3 of 4 android app components can be activated by passing an Intent but Content Provider is activated when a request method of Content Provider is called by Content Resolver.