return from maximize screen

Hi all, I'm embarrassed 😊 to ask this, but I can't remember how to get out of this. I've been away from using my computer for months and now I'm stuck.

I know this was changed a few updates ago, but for the life of me I can't remember the steps.

My wife was viewing something the other evening and wanted to make it bigger. She hit the green button at the top left of the screen to maximize it. Well, it did maximize it, but we lost the header and toolbar. I know you're all laughing right now, but like I said, I just can't remember the steps to get it back to "normal".

Will someone please put me out of my misery and tell me how to return to the view we had before she hit the green/maximize button?

thanx, Jack