I&m sure most Mac users know Command-C means copy and Command-V means paste, but there a host of other useful shortcuts that make a Mac user life much easier.
I&ve assembled this short collection to illustrate this truth:Command-WCloses the active window you are currently in.
Use Option-Command-W to close all currently active app windows.[ Further reading: 40 tips to get the most from your Mac (and macOS 'High Sierra') ]Command-Y