Learn how to use two apps simultaneously on the same screen with the split screen option on your Android. This feature is only available on Android Nougat (7.0) and its later versions and is not compatible with all applications.
Steps

Step 1. Open a first application
Some applications do not support multi-window mode. If you want to test this mode with two apps that support it, try using your built-in Android messaging and email apps.

Step 2. Press the home button
It is located at the bottom center of your screen.

Step 3. Open a second application
You now have at least two applications running.

Step 4. Tap the Recent Apps button
It is usually found at the bottom right of the screen. The overlay maps of recently opened apps are displayed.
The Recent Apps button may be located at the bottom left of the screen on some phones and tablets

Step 5. Long press the title bar at the top of an app
The text Drag here to use split mode should appear at the very top of the screen.

Step 6. Drag the app to Drag here to use split mode
The selected app now occupies the top half of the screen, while your other app (s) remain at the bottom of the screen.

Step 7. Tap the title bar of another application
Both apps are now displayed simultaneously on the same screen.

Step 8. Move the dividing line to change the size of the windows
This black bar of demarcation separates the two applications which are open.
- Move the row up to increase the size of the bottom app, or down to increase the size of the first app.
- If you move the row all the way up or down, you exit multi-window mode.

Step 9. Tap Recent apps to choose another app
Since you are in multi-window mode, recent apps appear differently and instead of seeing overlapping maps, you can choose another app to replace the one in the bottom window, just by tapping on its title bar.

Step 10. Put one of the applications in full screen to exit this mode
If you drag the demarcation line all the way up, the application in the bottom window will appear full screen. If you drag the line all the way down, the application in the top window will display in full screen.