Observed in the Low Latin as capitanus, associated with the Latin capitis referring to caput, for ‘head’ in the sense of leadership or main figure, with the Indo-European root in *kaput, for ‘head’. The linguistic roots express their association in ‘capital’ (capitālis), ‘capo’ (popular in the context of the mafia, for ‘Italian capo’ referring to the Latin caput), ‘decapitate’ (established in the Latin decapitāre) and capicúa (configured in the Catalan cap-i-cua, joining cap, for ‘head’ and cua, for ‘tail’).

It is a command rank that is formally or popularly applied in multiple fields, concerning the selection of the leader of a group, however, posing a clear distinction since the mid-fifteenth century in the military context being considered largely in the Navy.