Not all macOS applications run smoothly, with some running into troubles that prevent you from quitting it. Here’s how you can use force quit an app to stop it from running when nothing else works.
Most Mac users will have encountered an app that simply won’t close at some point in their computing career. Attempting to stop the app through normal means, such as “Quit” options in the menu, doesn’t work in such situations, leaving the app running with seemingly no answer to how to turn it off.
Those new to macOS may panic and decide that turning off their Mac is the only way around the problem. However, this may not be a solution, especially if it is an app that launches at boot.
Read more at AppleInsider.com