Jim Gordon who is also called Commissioner Gordon is an ally and friend of the superhero known as Batman. Commissioner Gordon was created by Bob Kane and Bill Finger and first appears in Detective Comics issue 27. It is worth noting that Jim Gordon was the first supporting character added to the Batman comics.
In nearly all versions of the Batman mythology Gordon is either a police officer of a police commissioner in Gotham City. Most police officers in Gotham City are crooked or even worse villains, however Gordon is different and shares the same hatred for evil that Batman does, and because of this both characters become close allies. Gordon is still sceptical of the dark knight’s tactics but deep down he knows that the methods used are needed to clear up the villains on the streets of Gotham City.
Gordon was the father/step father depending on which version of the comics you read of Barbara Gordon who became the first Batgirl. Barbara was later paralyzed by the joker. Gordon in most versions of the mythology is the one who creates and uses the bat symbol, and it is an ongoing joker between comic book readers that Batman will often disappear when Gordon is talking to him while in mid sentence or when he turns his back.
Gordon often wears a trench coat and a fedora while sporting a thick moustache. Commissioner Gordon in the most recent form was played by the actor Gary Oldman who fits the look and feel of the comic book character excellently.