Abitare means reside, vivere means live. I guess "abito" is a bit more formal/burocratic. Both are commonly used, they express the same idea.

Suppose somebody meets the following circumstances: 1) he is a commuter, 2) his house is at Ostia (40 kilometers from Rome, on the seaside) 3) the school where he teaches is in Rome 4) his girlfriend lives in Rome, and she often invites him and cooks for him. In this case he should say: Abito a Ostia, ma vivo a Roma and NOT: Vivo a Ostia, ma abito a Roma (would be a false statement)

There isn't difference, they are both used.