What is true about tragedy?

Tragedies, in the classical sense, were plays where usually a conflict between the society and an individual were presented. In them, the individual would often be someone who opposed what he thought was not just or was wrong and for that the person would die in the end which is why it's tragic. The person would usually be someone who is better than us so their death would serve as catharsis, that is, the purification of all emotion and fears through art.