Laura Mulvey
My understanding:
The objectification of females in the media through the male gaze. The male-gaze is when a female is represented in a way a man would like to see her.
The male-gaze forces the audience to identify with the protagonist, who is likely to be male; this is done through point of view shots through the males point of view. The female in the media is there "to-be-looked-at" or as Mulvey would say, she would have the quailty of "to-be-looked-at-ness"

Do i believe in the theory?
I think that Mulvey's theory is true, in any media text the theory of male-gaze and female objectification can easily and always be found. But media texts are trying to chage this, however, there will always be 'male-gaze' and 'objectification'; especially as most directors are male.