A regiment is a military unit, compose of a variable number of battalions – commanded by a colonel. Depending on the nation, military branch, mission, and organisation, a modern regiment resembles a brigade, in that both range in size from a few hundred to 5,000 soldiers (3 to 7 standard battalions). Generally, regiments and brigades are grouped as divisions. The modern regiment's size varies in number, scope, and administrative role from country to country (and might not exist in some military forces) and sometimes even within the military of the same nations.