In bodybuilding everybody wants big biceps, as they are a most impressive area to develop, and given their high visibility and superficiality, signify strength perhaps like no other body part. When someone asks, "flex a muscle" they do not want to see your calves. It is the biceps that are usually requested.

Also, the greatest professional bodybuilding champions are usually those who are known for tremendous biceps size and shape. From the Austrian Oak, Arnold Schwarzenegger, through to current Mr. Olympia, Ronnie Coleman, great champions usually possess great biceps.
The biceps grouping (anatomically known as the biceps brachii), of which there are two heads (the short head or outer biceps, and the long head, or inner) comprise the upper portion of the upper arm and are responsible for elbow flexion (moving the hand toward the shoulder), elbow supination (rotating the palm upwards), and shoulder flexion/transverse flexion.
Also associated with the biceps, although not part of their anatomical structure, are the brachialis and brachioradialis, muscles that are situated on the side of the arm between biceps and triceps, and connect the main bicep muscle to the forearm respectively.

Training the biceps will involve training these muscles also, as they allow for greater overall upper arm size, and the illusion of a larger biceps from top to bottom.

To become a bodybuilding champion, or just someone who would like to look great on the beach, training the biceps and associated muscles is a must. This article will provide an overview of the best exercises currently available, a full training program and tips to get the most from the methods presented.

en.wikipedia.org/wiki/Biceps_brachii_muscle