Computerworld - https://www.computerworld.com/article/3023544/apple-mac/21-keyboard-shortcuts-mac-users-need-to-know.html#tk.rss_all
I’m sure most Mac users know Command-C means copy and Command-V means paste, but there’s a host of other useful shortcuts that make a Mac user’s life much easier. I’ve assembled this short collection to illustrate this truth:
Closes the active window you are currently in. Use Option-Command-W to close all currently active app windows.
Press this combination to minimize the front app window to Dock, or press Command-Option-M to minimize all the windows belonging to the front app.
Command and Option
If you can’t see your desktop for all the open applications, just hold Command and Option down and click anywhere