I am fully aware that closing all unused programs frees a lot of memory.
My question is : do I have to go thru the sometimes 3 or 4 step process of hitting the Menu button and then Close (time-consuming), or is it functionally the same to hit the Back button (not the red, Close button) repeatedly ??
Thanks to those that will reply.

Some apps close completely with the back button, some do not. Best practice is to use the menu >> close/exit.

Thanks, Devnull.
Actually, by application I don't mean any aftermarket/commercial applications, but rather something like "Media", "Camera", "Browser", etc...

Again, some do, some don't.

For instance, the browser has an option to "Close Browser on Escape". Notice I said "option".

Another is the media player... If a song or video is playing and you hit the back(Escape) button, it keeps playing in the background and does NOT close.