Cattle are the domesticated forms of the once wild aurochs. They have been breed over the ages to give us almost 2000 different breeds today. Some are bred with wild forms such as yaks or bison to give even more bizzar breeds. Each breed has unique characteristics that make set it apart from others. While there are too many breeds to name each here, we are picking out the most common ones to show you the vast diversity in this species.
Africander: Cattle from this breed were breed originally in South Africa, originating from the Hottentot cattle. They have a typical sanga type with a small neck hump, a large dewlap and lateral horns (although some have no horns). This breed is generally red in color and extremely tolerant of heat. It was imported to the King Ranch and exists in several southern places in the US.

Angus: Cattle from this breed ...

Ankole-Watusi: Cattle from this breed ...

Aubrac: Cattle from this breed ...

Ayreshire: Cattle from this breed ...

Barzona: Cattle from this breed ...

Beefalo: Cattle from this breed ...

Beefmaster: Cattle from this breed ...

Belgian Blue: See How Belgian Blues are Selectively Bred for Double-Muscling in this Video. [1]

Blonde d'Aquitaine: Cattle from this breed ...

more to come ...
Links:
[1] http://www.youtube.com/watch?v=Nmkj5gq1cQU