The number of Jokers in DC Comics varies depending on different storylines and continuities. Sometimes there's just the classic Joker, but in some multiverse scenarios, there can be alternate or variant versions of him.
Jokers comics typically have a lot of action and adventure. They might have a gritty tone and deal with themes that challenge conventional norms. The visuals are usually very detailed and eye-catching.
Well, one origin story of the Joker is that he fell into a vat of chemicals which disfigured him both physically and mentally. This accident was a turning point that made him the chaotic and unpredictable villain we know. He then developed his twisted sense of humor and a vendetta against Batman.
One back story could be that the joker was once a normal person but was driven mad by a series of cruel pranks played on him. Another might be that he was born into a chaotic and unforgiving family environment which shaped his twisted personality. And the third could be that he had a great fall from grace in a magic show gone wrong, turning him into the joker we know today.