structural:reformatting, quality:correction, linguistic:paraphrasing, structural:scholar_edition
Commands, formations, and units

It is common, at least in the European and North American militaries, to refer to the building blocks of a military as command s, formation s, and unit s.

In a military context, a command is a collection of units and formations under the control of a single officer, although during World War II a command was also a name given to a battlegroup in the United States Army. In general, it is an administrative and executive strategic headquarters that is responsible to the national government or the national military headquarters. It is not uncommon for a nation's services to each consist of their own command (such as Land Component, Air Component, Naval Component, and Medical Component in the Belgian Army), but this does not preclude the existence of commands that are not service-based.

A formation is defined by the U.S. Department of Defense as "two or more aircraft, ships, or units proceeding together under a commander". Fomin in the Great Soviet Encyclopedia emphasised its combined-arms nature: "Formations are those military organisations which are formed from different speciality Arms and Services troop units to create a balanced, combined combat force. The formations only differ in their ability to achieve different scales of application of force to achieve different strategic, operational and tactical goals and mission objectives." It is a composite military organization that includes a mixture of integrated and operationally attached sub-units, and is usually combat-capable. Examples of formations include divisions, brigades, battalions, wings, etc. Formation may also refer to tactical formation, the physical arrangement or disposition of troops and weapons. Examples of formation in such usage include pakfront, panzerkeil, testudo formation, etc.

A typical unit is a homogeneous military organization (either combat, combat-support or non-combat in capability) that includes service personnel predominantly from a single arm of service, or a branch of service, and its administrative and command functions are self-contained. Any unit subordinate to another unit is considered its sub-unit or minor unit. It is not uncommon in the United States for unit and formation to be used synonymously. In Commonwealth practice, formation is not used for smaller organizations such as battalions, which are instead called "units", and their constituent platoons or companies are referred to as sub-units. In the Commonwealth, formations are divisions, brigades, etc.

Different armed forces, and even different branches of service of the armed forces, may use the same name to denote different types of organizations. An example is the "squadron". In most navies a squadron is a formation of several ships; in most air forces it is a unit; in the U.S. Army it is a battalion-sized cavalry unit; and in Commonwealth armies a squadron is a company-sized sub-unit.