Can someone explain the differences in layman's terms? I am a possible noobie to the Audi experience and was asked this question.

Is a 2001 A6 2.8L normally one of these?

 

multi valve are mostly interference which meas in 95% it will damage the valves if the timing belt broke ( valve strike ) none interference is a gray area because valve damage is still apparent and I would put that at 70%, rule of thumb is to change the timing belt before you take it to the garage because regardless of interference and none interference the cams might have stopped in the safe position

 

Interference means the valves and the piston occupy the same space in the cylinder, but not at the same time. The timing of the engine opens/closes the valves so they don't strike the piston when the piston is at the top of the cylinder. If the timing belt breaks or slips, this synchonization is lost and the valves and piston can hit. This results in bent/broken valves and a damaged piston head. Car no run.

Non-interference means they cannot hit each other, even if the timing belt breaks/slips. Car still no run, but no damage either.