Android N adds support for displaying more than one app at the same time. On handheld devices, two apps can run side-by-side or one-above-the-other in split-screen mode. On TV devices, apps can use picture-in-picture mode to continue video playback while users are interacting with another app.
In below picture, you can see two apps running side by side.
In below picture, you can see two apps running side by side.