The leader of the hierarchy is still System, though. Think of it as an army. You'd have a Private who is subordinate to a Sergeant. The Sergeant would be subordinate to a Captain. And the Captain would be subordinate to a General. If the General wanted something done, he might ask the Captain to do it for him. The Captain would get the Sergeant to do it, and the Sergeant would then pick on a poor Private. So Button would be the Private, Forms would be the Sergeant, Windows would be the Captain, and System the General.
In other words, there is a chain of command in NET programming. And if you don't follow the chain of command, you're in trouble!
But you see this chain of command every time you type a full stop and a pop up box appears. When you're selecting an item from the list, you're selecting the next in the chain of command.
This code at the top of the form window: