Muscle found on the top half of the arm, made up of the long head and the short head muscular bundles. Both link in to the elbow joint and both link in to different parts of the scapula, or shoulder blade, for those unfamiliar with the precise workings of that most noblest and erotic of things: the shoulder.
One of the easiest muscles to develop in bodybuilding training.
Culturally an important thing for men to cultivate, if he ain't got no biceps he ain't gonna be helpin you move that couch. Flexes the elbow and looks impressive. If you want to spend hours on it. Hours that could be spent fellating the neighbour's dog.
Despite the prominence of the bicep muscle it plays little role in actual strength and punching power, as far as the arm is concerned the triceps muscles are far more powerful as they are made up of three, larger heads and move both the shoulder and forearm.
The biceps maketh the man. Biceps are made not born.
If you were a bicep you'd want to be big and powerful wouldn't you. Remember that.