A brigade is a military unit in an army. Currently in most armies, a brigade is made up of several thousand soldiers in Battalions plus a Brigade Headquarters. This is common in the United States Army. Before World War II, a brigade had several regiments. The United States Army has several types of brigades. These brigades have usually a Headquarters Company and usually several battalions.
An artillery brigade in the United States Army has a Headquarters Battery and several battalions from different regiments. Each battalion in a United States Army Artillery Brigade may have High Mobility Artillery Rocket Systems (HIMARS) and/or Multiple Launch Rocket Systems (MLRS) Units assigned to it.
Depending on the country an army brigade is under the command of a Brigadier General, Brigadier or Colonel.