Android activity difference between active and running

Question

I was reading the Android documentation on the Android developer website and I read the following near the Android Activity Lifecycle:

If an activity in the foreground of the screen (at the top of the stack), it is active or running.

What is the difference between active and running? It says that they are both on the foreground of the screen, so I can't see the real difference between those states.

Answer 1

An activity can still be running, but it is not active, whenever it is still visible on the screen, but partially obscured by another activity.