What is the difference between army brigades and regiments?

Answer 1

Three regiments make a division, thus, a division is three times the size of a regiment.

However in the US Army.

A Regiment was a sub-unit of a Division. During WW1 the Infantry Division consisted of 4 Infantry Regiments, divided into 2 Brigades. Thus a Division contained two Brigades and each Brigade contained 2 Regiments plus there were 2 Artillery Brigades of 2 artillery Battalions. At the beginning of WW2, the US Army wanted to reduce the size of its Infantry Division so they were more maneuverable on the battle field. The Brigades command level was eliminated and 1 Infantry Regiment was deleted. So an Infantry Division contained 3 Infantry Regiments and 3 Artillery Battalion(later increased back to 4) and an Engineer Battalion and support units of Medical, QuarterMaster, and other units. The size of the Infantry Division was about 15,000 men. However, since the support units that were not part of the Regiments, that means the Regiment was NOT 1/3 the size of the Division. The Regiments contained about 3,000 men. Each Regiment contained 12 Rifle Companies, identified by Letters A thru M(excluding "J"). The Regiments were grouped into 3 Battalions. So 1st Battalion(as it was called) contained Companies A, B, C & D, where the fourth one, Company D, was a heavy weapons company that supported the other three. A company contained 250 men. There were other support units and a Headquarters Company attached to each Battalion of the Regiment. An Airborne Division was organized very similar to the infantry division except it only had 9 companies per Regiment and the total size was 9,000 men. See Link with simple diagrams that explain the Organization of the US Army Division.

Answer 2

Regiments are usually homogeneous units fixed by type and not usually self-sufficient when operating in the field. A Regiment is usually three battalions. A Tank Regiment has tank battalions; an Infantry Regiment has infantry battalions, and so forth. A regiment is usually commanded by a Colonel. A regiment almost always operates as part of a division (of 3-5 regiments plus support). Some nations have used the term "Regiment" to apply to mixed Infantry & Armor units (above battalion level). The division supplies the artillery, engineer & logistics support to the regiment. A Brigade may be part of a division or not. A Brigade is most often a mixed type unit with 2-5 battalions, usually created with a specific use in mind. An Armored (or Tank) Brigade may have two Tank Battalions, one Mechanized or Motorized Infantry Battalion, and one Artillery Battalion, plus several company sized units that provide engineer, logistics, maintenance, and/or transportation support. An Infantry Brigade may have tanks or not. The organization of a Brigade is flexible, and can often operate independently in the field. The brigade can be commanded by a Colonel or Brigadier General. The brigades' normal purpose is to organize and fight together as a combination of the three primary combat arms: infantry, armor, & artillery. Since the advent of helicopters, they have been added to these organizations in various capacities. The Brigade had greater usage as a combined arms team after World War One, and that use accelerated after World War Two. The US Armored Division in the last half of World War Two used the term "Combat Command" which was the size of a Regiment or Brigade. The US Armored Division had three of these: CCR (Combat Command-Recon), CCA (Combat Command A) & CCB (Combat Command B). The Division Commander could move battalions and/or companies between Combat Commands as the situation required. In the modern US Army, the term "Regiment" is used primarily for historical & heraldry purposes when referring to the specific name of a battalion. The US Army is organized to fight in the field more as (combined arms) brigades than as regiments. For example an Armored Division will normally have three combat brigades plus various supporting units of battalion or company size. One Brigade may have one armored battalion, two mechanized infantry battalions, and one self-propelled artillery battalion. These battalion names may be for example: 1st Battalion 63rd Armored (Regiment); 1st Battalion 52nd Infantry (Regiment); 1st Battalion 54th Infantry (Regiment); and 1st Battalion 78th Artillery (Regiment). In WW2 the 1st Battalion 52nd Infantry would have fought alongside the 2nd & 3rd Battalions of the 52nd Infantry Regiment. The 1st Battalion of the Regiment would have Companies A, B & C. The 2nd Battalion would have companies D, E, & F. The 3rd Battalion would have companies G, H & I for example. Some battalions had four companies each. Tanks & Artillery would be allocated to help in combat by the Division Commander.