Sophocles was born to a wealthy family in Attica, around 496 BC. In 468 BC, he took first place in the Dionysia, the festival at which plays were judged. According to Plutarch, the judging system was changed that year, which may have allowed Sophocles to win over Aeschylus.
He lived until he was about 90. One of the stories about his death is that he injured himself trying to recite a particularly long sentence from 'Antigone', though that is probably simple legend. His contemporaries said that he died happy.
Sophocles introduced a third actor to the stage, which enriched the possibility for conversation. According to Aristotle, he also was the first to include painted sets. After Aeschylus died, he was the undisputed master writer of tragedies. He wrote more than 120 plays, but only seven survive to this day.
To my admittedly amateur eye, his work is richer than that of Aeschylus, at least in the selections for this months reading. The characters have more depth. They seem more like actual people with conflicts and less like archetypes. Since both playwrights have more than 100 lost plays, this may be a completely unfair comparison.