I'm curious on how the system shows faults

When you clear the faults, do all faults clear

When you see a fault, does it just show you the fault and how many times it had occurred. Meaning 3 faults. Or does it get more detailed like during 30 ignition cycles, it's faulted X times. Or does it even show at what mielage.

How far back does it show *old faults* or how does a mechanic set a baseline based on what *faults* he may see but you don't see any fault lights on the dash.

Just curious...