A company typically has 100 to 200 soldiers, and a battalion is a combat unit of 500 to 800 soldiers. Three to five battalions, approximately 1,500 to 4,000 soldiers, comprise a brigade. The size of a division varies from about 10,000 to 18,000 soldiers, and most divisions have three or more brigades of roughly equal size. A corps, which consists of two or more divisions and support troops, normally has from 50,000 to 100,000 soldiers. Artillery groups are known as batteries, and groups of cavalry are called troops. The division is the basic fighting unit of many armies. Divisions include infantry, armored, artillery and engineers, who are sometimes considered combat troops. Divisions also have support troops for transportation, medical care and other jobs.