What is the offical name of the third on-screen button?

I am searching for the official name of the third (right) Android on-screen button. |Android version|On-screen buttons| |-|-| |1-4.4|| |5.0+|| The left and middle buttons are clear: - Left: **Back** button - Middle: **Home** button - Right: ??? Please include a reference where the name of the third/right button is stated in your answer.