Terminology of Military Units – Part 1: Infantry Formations, Divisional Level and Below

With military operations in Afghanistan in the news, and Iraq before that, people with little understanding of how the military are organised are coming across terms like regiment, battalion, brigade, etc. This article is an attempt to explain these terms to the layman. Being aimed at an English-speaking readership, it is based on the terminology used in the British and American armies, though much of that will apply to all regular (i.e. not guerrilla) armies worldwide.

I’ll start from the smallest unit type and working upwards, beginning with the infantry then moving on to other arms such as armour (tanks) and artillery in later parts.

Section:a group of about 8 to 12 infantrymen with one or two light machine guns to give them firepower, usually led by a corporal. Might be divided into two ‘fire teams’ so that one can give covering fire to the other as it advances, but these teams aren’t usually permanent units so I’ve not included them in this list. In armoured infantry or mechanised infantry units, the section will travel together in an armoured personnel carrier (APC) or infantry fighting vehicle such as the UK Warrior or the US Bradley. Doesn’t usually operate on its own in battle, though for patrolling and other peacekeeping operations a section can be an ideal size to send out from a base as it is capable of defending itself but not so big as to be provocative.

Platoon: a unit of around 4 sections, so 40 to 60 men. Commanded by a lieutenant or a senior sergeant. Might also have a few support weapons such as a light mortar or an anti-tank rocket launcher. Usually considered the smallest unit that can launch an attack as it has enough sub-units to keep a small reserve and also send a section to work round the enemies’ flanks as well as attacking the front.

Company: a unit of around 3 or 4 platoons, say 200 to 300 men. Usually commanded by a captain or a major. Most of the platoons in a company will be ordinary infantry platoons (sometimes called rifle platoons), but often there will be one support weapon platoon with mortars and possibly heavier machine guns for sustained fire (the light machine guns used by the individual sections are more designed for short bursts of fire).