ABSTRACT: The polysemic term "competences" has been developed from different approaches and models in the international context. The results of this investigation are shown through five models of professional competences, related with their corresponding international certificate of competence. The models are classified according to the theoretical approaches developed by differents authors from a broad perspective: exogenous, endogenous, external and holistic. According to their assumptions implicit or explicit when formulate their hypotheses. With each model of competence, a brief description its historical context is made in order to clearly establish the characteristics and principal findings. Finally, the models are analyzed and compared. Keywords: professional competences; competence; certification systems.