The Personnel Complement Of The Different Military Units

A troop has different specific meanings in different armed forces, Generally a single soldier is referred to as troop

Squad: 4 to 10 soldiers depend on mission

Platoon: 3 to 4 squads about 16 to 40 soldiers usually led by 1st or 2nd lieutenant

Company: 3 to 4 Platoons 100 to 200 soldiers usually led by captain
And if you're Cav (Cavalry) this level is called a "Troop"

Battalion: 3 to 5 companies 500 to 900 soldiers usually led by lieutenant colonel
And if you're Cav (Cavalry) this level is called a "Squadron"

Brigade: 3 to 5 battalions 3000 to 5000 soldiers usually led by colonel
And if you're Cav (Cavalry) this level is called a "Regiment"

Separate Brigade: A separate brigade is a standalone, self-sustaining unit capable of carrying out certain missions totally on its own. It is usually led by a one-star general. A one-star is called a Brigadier General, hence the reference to brigade.

Division: 3 brigades 10,000 to 18,000 soldiers led by two-star general who is called a Major General

Corps: 2 to 5 divisions 20,000 to 90,000 soldiers led by three-star general who is called a Lieutenant General

Field Army: between 2 and 5 corps 100,000 to 250,000 soldiers led by four-star general who is simply called General. When referring to a specific service different words are used (singular or plural):

* United States Navy - Sailor
* United States Air Force - Airman
* United States Army - Soldier
* United States Marine Corps - Marine
* United States Coast Guard - Coast Guardsman
* United States National Guard - National Guardsman