What is" automatic pinning", and how does it work?

Question

In plank preferences there is an option: Automatic Pinning

How does it work?

I enabled and disabled the option but failed to identify any difference.

Answer 1

Automatically pinning is a feature where Plank will pin items when you move an item that is not currently pinned. For example if you open Files, its icon will appear in the dock temporarily and be removed when you close it. However if you move the icon in the dock to another position, it will now be pinned and stay in the dock even when the app is no longer running.