A brigade group is a term used primarily in armies

Army

An army An army An army (from Latin arma "arms, weapons" via Old French armée, "armed" (feminine), in the broadest sense, is the land-based military of a nation or state. It may also include other branches of the military such as the air force via means of aviation corps...

 of the Commonwealth of Nations

Commonwealth of Nations

The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 for an ad hoc arrangement of forces and not a permanent organisation whereas, with a capital G, a Brigade Group is.

It generally refers to a formation which includes three or four battle groups

Battlegroup (army)

A battlegroup , or task force in modern military theory, is the basic building block of an army's fighting force. A battlegroup is formed around an infantry battalion or armoured regiment, which is usually commanded by a Lieutenant Colonel...

, or an infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 brigade

Brigade

A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

 (three battalion

Battalion

A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...

s), supported by armoured

Tank

A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...

, artillery

Artillery

Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

, field engineer, aviation

Military aviation

Military aviation is the use of aircraft and other flying machines for the purposes of conducting or enabling warfare, including national airlift capacity to provide logistical supply to forces stationed in a theater or along a front. Air power includes the national means of conducting such...

 and support units, and amounting to about 5,000 soldiers. A brigade group represents the smallest unit able to operate independently for extended periods on the battlefield. It is similar to the concept of a regimental combat team

Regimental combat team

A regimental combat team was a provisional major infantry unit of the United States Army during the World War II and the Korean War, and of the U.S. Marine Corps to the present day...

 (RCT), which was once used by the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

, but which now uses the term brigade combat team

Brigade combat team

The brigade combat team is the basic deployable unit of maneuver in the US Army. A brigade combat team consists of one combat arms branch maneuver brigade, and its attached support and fire units. A brigade combat team is generally commanded by a colonel , but in rare instances it is commanded by...

(BCT). The United States Marine Corps

United States Marine Corps

The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

continues to use the term regimental combat team.