Military operations can be classified by the scale and scope of force employment, and their impact on the wider conflict. The scope of military operations can be:
Theater: this describes an operation over a large, often continental, area of operation and represents a strategic national commitment to the conflict, such as Operation Barbarossa, with general goals that encompass areas of consideration outside the military, such as the economic and political impact of military goals on areas concerned.
Campaign: this describes either a subset of the theatre of operation, or a more limited geographic and operational strategic commitment, such as the Battle of Britain, and need not represent total national commitment to a conflict, or have broader goals outside the military impact.The United States just recently got out of some of the longest conflicts in the Military history. Operations Enduring Freedom and Operation Iraqi Freedom are some of the most recognizable campaigns as they have to do with the Iraq and a Afghanistan conflicts.<Owens, John, Charles, 2008)>
Battle: this describes a subset of a campaign that will have specific military goals and geographic objectives, as well as clearly defined use of forces, such as the Battle of Gallipoli, which operationally was a combined arms operation originally known as the "Dardanelles landings" as part of the Dardanelles Campaign, where about 480,000 Allied troops took part.
Parallel to and reflecting this framework for operations are organized elements within the armed forces which prepare for and conduct operations at various levels of war. While there is a general correlation between the size of units, the area within which they operate, and the scope of mission they perform, the correlation is not absolute. In fact, it is ultimately the mission that a unit performs that determines the level of war within which it operates.
— David M. Glantz, Soviet Military Operational Art