Mac keyboard shortcuts Just for my curiosity and knowledge, I just learned that CMD + M will minimize and bring to the dock the active application.  But what is the opposite shortcuts in order to bring back the application to the screen from the dock?

Thank you so much and have a wonderful day.
No need to try all key combos until it works, because you'll be disappointed. Check out this page from Apple Support, and you'll find, sadly, there is no reverse key combo because Finder has nothing to work with - no focus for the command.

Once the window is closed, not even Command - Tab > [minimized app icon] will open the app window!

The only way to open the app is to click on its icon in the Dock.