# The Fundamentals

"The Fundamentals" of Android primarily concentrate on 5 components; Activities, Services, Broadcast Receivers, Content Providers, and Intents. **Activities** are essentially what you see on your screen; each screen in an app is a separate activity. **Services** run in the background to perform long-running operations or to perform work for remote processes. They do not provide a user interface. **Broadcast Receivers** respond to broadcast messages from other applications or from the system itself. These messages are often in the form of Intents. **Content Providers** manage a shared set of app data that other apps can query or modify, through a structured interface. Finally, **Intents** are messaging objects which facilitate the communication between the aforementioned components. Understanding these five core concepts is key to mastering Android fundamentals.