giant impact theory - the moon was formed from the collision between earth and another mars-sized body.
colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.
capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.
accretion hypothesis - the moon was formed from collisions and combining of planetesimals.
i think this is right, if not and you know better let me know.