A commander-in-chief is the commander of a nation's military forces or significant element of those forces. In the latter case, the force element may be defined as those forces within a particular region or those forces which are associated by function. As a practical term it refers to the military competencies that reside in a nation-state's executive, head of state or government. Often, a given country's commander-in-chief need not be or have been a commissioned officer or even a veteran, and it is by this legal statute that civilian control of the military is realized in states where it is constitutionally required.