This document discusses definitions of communicative competence that have been proposed since the late 1960s. It outlines several influential definitions, including Hymes' definition which expanded on Chomsky's notion of competence to include sociolinguistic ability. The document also describes three models of communicative competence that are commonly used in research: the models proposed by Canale and Swain, Bachman and Palmer, and those described in the Common European Framework. It focuses on distinguishing between competence, capacity, ability and performance as conceptualized in different definitions.