Most Android apps consist of regions referred to as the [system bars](https://developer.android.com/design/ui/mobile/guides/foundations/system-bars),
the navigation area, and the body.
![](https://developer.android.com/static/images/design/ui/mobile/app-anatomy_parts.png) **Figure 4:** Parts of an Android app: systems bars (1), navigation area (2), and body (3)

## System bars

The status bar and navigation bar--collectively known as the system bars--display
important information such as battery level, the time, and notification alerts,
and provide direct device interaction from anywhere. Read more about [system
bars](https://developer.android.com/design/ui/mobile/guides/foundations/system-bars).
![](https://developer.android.com/static/images/design/ui/mobile/app-anatomy_parts_bars.png) **Figure 5:** System bars (1)

## Navigation region

Navigation represents the different affordances that allow a user to
navigate within your app, access important actions, or across the Android
platform.

## Body region

The body region holds the screen content. Body content is composed of additional
groupings and layout parameters. It must continue under navigation and system
bar regions.

Declare \[\`WindowCompat.setDecorFitsSystemWindows(window, false)\`\]\[5\] for
edge-to-edge insets.
![](https://developer.android.com/static/images/design/ui/mobile/app-anatomy_body.png)

To determine the appropriate composition and navigation patterns for your
layout, seek to understand how users interact with your content, and how they
navigate your app's information architecture. This understanding can guide your
design toward being more user-focused by creating UI that users can act on.