is there any difference between lineal champ and undisputed champion?

ok, this is something i've never paid much attention to because i dont really care that much, but what are the differences between all the types of champion you can be... here's my understanding as of now, but i could be way off... Paper champ - you hold a belt (wbo, wba, ibf, wbc. dont even know if wbo belongs in there???) Undisputed champ - you hold the wba, ibf, and wbc betls. Lineal champ - you beat the guy who held the title of lineal champ before you (how did that guy get that title? and did that guy have to hold a belt?) Ring champ - the guy that ring magazine calls the champ, but what is their criteria???