The article analyzes the concepts of “Ability”, “Professional suitability”, “Professional psychological selection”, in the development and understanding of which a significant contribution was made by E.A. Klimov. Professional psychological selection is considered as a system, the systemforming factor of which is the professional suitability of a person who chooses a specific profession. The content of the concept of ability includes the motivation and experience (knowledge, skills, and abilities) of the individual, by analogy with the dynamic functional structure of personality developed by K.K. Platonov. Its own definition of the term “Abilities” is presented.