It is the theory that every young boy has a desire to sleep with his mother and take his father out of the picture. Freud was the one who developed the theory.

This complex is also based off of a work of fiction. There was a guy named Oedipus who was sent away as a child. He fell in love with this woman who happened to be his mother and killed his father. I'm pretty sure there was some kind of curse on them or some prophecy that this was supposed to happen which is why they sent him away as a kid. But then the prophecy ended up being fulfilled anyway.

like most of Freuds work, the Oedipus complex is the subject of contraversy. basically it explains the early years of development that all boys go though, at a young age they all fall in love with their mothers, and because of this they begin to resent their fathers and fantasise about killing their fathers and taking their place. however boys will then notice girls, and come under the belief that all girls are infact castrated boys (penises feature often in freuds theories). out of fear of being castrated for being bad, the boys will then form an emotional bond with their father and take on the morals of his dad. this is actually the "correct" way of going though the oedipus complex, any other way will result in the child growing up to become a sexual deviant with loose morals (we dont remember this, because of course we repress these memories) freud also made a model like this for girls called the "electra comlex" (ive spelt that wrong) which is basically a mirror of the oedipus complex, this model was never completed the important thing to remember about all this though, is that its riddled with faults and holes, freud actually thought up his theories first and then went out to find evidence for them (rather than studying then theorising). the entire study for the oedipus complex was based on one boy ("little hans") who freud never met, but rather studied though correspondence by getting his father to answer questions which were often leading (ie put words in the boys mouth) its also useful to note that freud never cured a single paitent, all paitents he says he cured continued to suffer mentally after his treatment