Gladiators were Roman slaves convicted criminals or volunteers who were trained to fight in the arena and in other places to entertain crowds. Romans further believed that gladiatorial combat pleased the gods and feared bad consequences if the games stopped. Gladiators underwent a rigorous training before being allowed or forced to fight. They had to take a religious oath before starting training. Gladiators were even trained how to die with decorum. They had to rise on one knee, assuming they were strong enough and grasp the thigh of the victorious gladiator. They had to die without screaming. It seems their rigorous training enabled them and motivated them to do this.
There were various different types of gladiatorial fights involving different techniques. There were also gladiators traind to hunt down and kill wild animals. There were even female gladiators. They were called gladiatrix (singular) or gladiatrices (plural). While they lived gladiators could enjoy the fame that successful pop stars can have today but their lives were put on the line, usually about five times a year.
Life expectancy of gladiators may have been marginally higher than for the Roman population as a whole because between fights they had better nutrition and better medical care than most Romans could afford. That may in part explain why some volunteered to become gladiators or stayed gladiators after being offered their freedom.