Resetting the Non-Volatile memory and System Management Controller is one way to troubleshoot problems with your Mac. But the methods for resetting those have changed with the latest hardware which include T2 chips. Most users will never have to deal with these, but if you do, learn Apple's recommended method for resetting these.
Links: Reset NVRAM or PRAM on your Mac, How to reset the System Management Controller (SMC) on your Mac, About the Apple T2 Security Chip.
My iMac pro was taking it’s sweet time waking up with a keyboard press then logging in with my Apple watch. Just did the SMC reset. Now it is almost instant! Went from 10 to 15 seconds to zero. Glad I read the list of symptoms this can fix.
I can'y thank you enoughfor your help in managing my Macs. When people in my office saw me do these things and how eforlessly they solved their problems they thought I was a wizard. I kept giving them your url hoping they'd be able to learn to tap your endless resources. One did and soon she got a better job.