Difference between ways to Copy Content Database från PROD to Dev Environment

I was looking for the best way to copy a SharePoint content database from PROD to Dev Environment, and found this (answered) question

It seems ok, but there was another answer below the accepted one. It seems that there already are a (simpler?) way doing this with a ps-commandlet.

My question is: What is the difference between backup-restore Content DB in SQL Manager and then runnning ps-command Mount-SPContentDatabase, vs Backup-SPFarm/Restore-SPFarm"

Is the latter only meant for use on same machine?