When most people think of cows, a large, amiable black and white animal probably comes to mind, but there are in fact a wide number of types of cattle, with almost a thousand cattle breeds being raised all over the world for a variety of purposes. Those black and white cattle you're thinking of, by the way, are dairy cattle from the Holstein breed, one of the most widely raised dairy cattle breeds in the world. Cows come in a range of shapes and sizes, for all sorts of purposes, and many people are working to preserve rare cattle breeds, along with the centuries of farming heritage that they represent.
Two major subspecies of cattle are domesticated: Bos taurus taurus, or taurine cattle, and Bos taurus indicus, or zebus. Taurine cattle are adapted for the cooler climates of the Northern Hemisphere, while zebus are better suited for hot, dry climates like those found in Africa. This has actually caused problems among some well-meaning aid organizations, which have exported taurine cattle to Africa to help people with famine conditions, only to discover that these cattle are not suited to the environment, requiring many more resources than zebus and ultimately proving to be more trouble than they are worth.
Types of cattle are generally broken up by purpose. Beef cattle, as you might imagine, are bred to yield large amounts of high quality meat, while dairy cattle have been bred to deliver copious milk with a high butterfat content. Draft cattle are bred to be working animals, pulling plows, carts, and other farm equipment. Multipurpose cattle can perform two or all three of these tasks, depending on the breed.
Some well known examples of beef cows include: Angus, Limousin, Longhorn, North Devon, Wagyu, and Hereford. Popular dairy breeds, in addition to the Holstein, include Brown Swiss, Jersey, Ayrshire, and Milking Shorthorn Cattle. These types of cattle all tend to be more lightweight than beef cattle, and many of them are smaller, as well. Jerseys in particular are renowned for their milk and gentle temperaments.
Belgian Blues, Charolais, Lourdais, Welsh Blacks, and Red Polls are all examples of mixed-use cattle. You can also found cattle bred specifically for sport, such as the cattle used in bullfighting and bullriding. A number of breeders have also developed zebu/taurine hybrids, taking advantage of the best traits of both subspecies to create especially strong, flexible types of cattle.