When employment ads state "must pass background check" what exactly does it mean?
They will check to see if you have been arrested and/or convicted of anything. If the job requires you to drive, they will check your driving records. Many companies do credit checks as well.
It essentially means they will varify to make sure that you didnt lie
You have to have a background check with no criminal history.
Normally would be a Criminal Records check, a driving record check, and in a lot of cases, a credit record check. And yes, it is totally legal.
They will run a credit and criminal check on you. Also, run checks on your references.