Sometimes that application you’re running just…won’t…budge. There are though three ways to Force Quit on a Mac.
Shortcut to Force Quit on Mac
Holding down the shortcut Option + Cmd + Esc brings up the menu seen above in macOS Catalina. You can also call up that menu by going to > Force Quit. (The remains in the top left-hand corner whenever you’re not in ‘full screen’ mode.) There, you can tap the application you want to close. Normally a failing application will be highlighted in red with (Not Responding) next to it. An alternative way to do this is holding down Ctl and tapping (i.e. right-clicking,) on the misbehaving app’s icon in the dock. This calls up a menu specifically for that application and Force Quit will be an option if it has failed.
Once you have taken one of these steps and closed down whichever piece of software was causing a problem you should be able to reopen it and have it run smoothly. If problems persist, you will probably want to reboot your Mac.