Cattle—colloquially cows—are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos taurus. Cattle are raised as livestock for meat (beef and veal), as dairy animals for milk and other dairy products, and as draft animals (oxen or bullocks that pull carts, plows and other implements). Other products include leather and dung for manure or fuel. In some regions, such as parts of India, cattle have significant religious meaning. From as few as 80 progenitors domesticated in southeast Turkey about 10,500 years ago, according to an estimate from 2003, there are 1.3 billion cattle in the world. In 2009, cattle became one of the first livestock animals to have a fully mapped genome. Some consider cattle the oldest form of wealth, and cattle raiding consequently one of the earliest forms of theft.

Cow is the nickname for cattle, and the name of adult female cattle.

cowsay is a program which generates ASCII pictures of a cow with a message. It can also generate pictures using pre-made images of other animals, such as Tux the Penguin, the Linux mascot. It is written in Perl. There is also a related program called cowthink, with cows with thought bubbles rather than speech bubbles. .cow files for cowsay exist which are able to produce different variants of "cows", with different kinds of "eyes", and so forth. It is sometimes used on IRC, desktop screenshots, and in software documentation. It is more or less a joke within hacker culture, but has been around long enough that its use is rather widespread. In 2007 it was highlighted as a Debian package of the day.