Commander in Chief (CinC)

Commander in Chief (CinC) – the most senior commander.
A nation's head of state (monarchical or republican) usually holds the position of commander-in-chief, even if a separate head of government holds adequate executive power. The executive branch ultimately depends upon the legislature's will in a parliamentary system. However, the legislature does not issue orders directly to the armed forces and therefore does not control the military in any operational sense. Governors-general and colonial governors are often appointed commander-in-chief of the military forces within their territory.
A commander-in-chief is sometimes referred to as supreme commander, sometimes used as a specific term. The term is also used for military officers who hold such power and authority, not always through dictatorship, and as a subordinate (usually) to a head of state (see Generalissimo). The term is also used for officers who hold authority over an individual military branch, particular branch, or within a theatre of operations.

Sources:

Commander-in-chief. (2023). Collins Online Dictionary. Retrieved from: https://www.collinsdictionary.com/dictionary/english/grenade

Dupuy, T. N., Curt, J., and Hayes, G. P. (1986). "Supreme Commander." Dictionary of Military Terms. New York: The H.W. Wilson Company.