Who are these guys?

Can somebody tell me who The Jonas Brothers are? Are they really brothers? Why do they wear ascots? Where did they come from? I only see pictures of them but they don't look anything like Hanson which was the last brother/boy band group I remember. I don't know any of their songs, mainly because I don't enjoy terrible music. I really have no idea who these guys are. Great hair though boys, seriously. Your look is so natural it looks like you don't spend any time on it at all.