Is batman and joker brothers

No, Batman and the Joker are not brothers. Batman, also known as Bruce Wayne, is a vigilante fighting crime in Gotham City, while the Joker is his arch-nemesis and a chaotic criminal. Their relationship is often depicted as one of deep psychological conflict, with the Joker embodying the chaos that opposes Batman's quest for order and justice. While they share a complex and intertwined history, they are not related by blood.