Android applications are built using various components, and two of the most fundamental ones are Activities and Services. These components allow your app to interact with the user and perform background tasks, respectively.
Activities
Activities are the building blocks of a user interface. They represent a single interaction with the user. For example, when you open an app and click on a button, the Activity associated with that button is launched.
Here's a list of common Activities in Android:
- MainActivity: The main entry point of the app.
- ListActivity: Used for displaying a list of items.
- WebViewActivity: Used for displaying web pages.
- PreferencesActivity: Used for displaying a settings screen.
For more information on Activities, you can read our comprehensive guide on Android Activities.
Services
Services are components that run in the background, independent of the user interface. They are used to perform long-running operations, such as downloading files or playing music.
Here are some common use cases for Services:
- Background Tasks: Perform tasks that don't require user interaction, such as downloading files or sending notifications.
- Media Playback: Play music or video in the background.
- Location Updates: Track the user's location in the background.
For more information on Services, you can read our detailed guide on Android Services.