Is it true that the Gladiators were always fighting to death?

Who were they? Where were they coming from? And where does their name come from? They were mainly slaves: in case the Romans resulted as winners, at the end of a battle, they would eventually enslave part of the defeated population, to use them as servants, as construction builders, and also as Gladiators. Since the famous Ben Hur came out, and because of other more recent movies, we have ...