Save time with Mac keyboard shortcuts

From Apple Support : 

"With keyboard shortcuts like Command-Tab to switch between apps or Option-Shift-Command-V to paste and match style, you can save time while working on your Mac." :

https://www.youtube.com/watch?v=r2xVvFVp3a4&list=PLIl2EzNYri0cCcsSWBssHUnBFUHEBIwa7&index=33