The present text is an overview of competency-based assessment from two main angles: the most significant theoretical foundation and the most important historical moments in the author’s opinion. This is achieved by analyzing five major topics: a historical analysis of the concept of competence and its use in education, a reference to the psychological foundations of competency-based assessment, an approach to the definition of competence, areas, and types of competences, and, finally, a reference to some of the methods that have enjoyed greater recognition in competency-based assessment within the field of education. This historical and conceptual overview of competency-based assessment mentions some representative authors from multiple areas of knowledge whose ideas allow us conclude that this reflection is not unique to a field such as education or pedagogy, or that its applications are restricted to classrooms or institutions. In particular, we may note the presence of various perspectives such as educational technology, linguistics, and psychology. These are the ones that apparently have been more greatly concerned with this issue.