Army corps
Army corps — An echelon of command and tactical formations that employs divisions, multifunctional brigades, and functional brigades to achieve objectives on land [Dictionary of Military and Associated Terms, 19].
Two to seven divisions and various support units make up an army corps, or a corps, which has 50,000 to 300,000 troops and is commanded by a lieutenant general. The army corps is the most significant regular army formation. However, in wartime, two or more corps may be combined to form a field army (commanded by a general), and field armies may be combined to form an army group [Encyclopedia Britannica].
U.S. Department of Defense. (2021). Dictionary of Military and Associated Terms. U.S.A.: Independently published.
Military unit. Encyclopedia Britannica. Retrieved from: https://www.britannica.com/topic/military-unit