i just watched the space Odyssey movies and was woundering what the monilif is soppose to repressent?

Answer 1

there is alot of speculation on that, and no one really knows, but I've heard its a physical representation of some abstract "major thing" (discovery, idea, change, event, enlightenment, etc).

Answer 2

...in an interview with Kubrick, from the September 1968 issue of Playboy, he had this to say about the speculation and interpretation of his film, and the elements & characters associated with same:

"You're free to speculate as you wish about the philosophical and allegorical meaning of the film—and such speculation is one indication that it has succeeded in gripping the audience at a deep level—but I don't want to spell out a verbal road map for 2001 that every viewer will feel obligated to pursue or else fear he's missed the point."

...despite being a very dissatisfying response, if you really think about it, he's right!!!