The Orientation on Your Android Tablet
Your Android tablet features a gizmo called an accelerometer. It determines in which direction the tablet is pointed or whether you’ve reoriented the device from an upright position to a horizontal one (or vice versa) or even upside down. That way, the information displayed on the tablet’s screen always appears upright, no matter how you hold it.
To demonstrate how the tablet orients itself, simply rotate the tablet to the left or right. Most apps change their orientation to match however you’ve oriented the tablet, such as the Home screen.
The rotation feature may not work for all apps, and it may not even work for the Home screen. In that case, open the web browser app to experiment with rotation.
Most games present themselves in one orientation only.
The onscreen keyboard is more usable when the tablet is in its horizontal orientation.
You can lock the orientation if the rotating screen bothers you.
A great application for demonstrating the Android tablet accelerometer is the game Labyrinth. You can purchase it at the Google Play Store or download the free version, Labyrinth Lite.