Introduction. Cognition is an essentially human attribute; a cultural entity and a precondition for social progress, in which categorisation and methodological significance play a key role. But the essence and functions of such categories can also cause disagreement in the scientific community. Hence the importance of understanding the origin, essence and meaning of categories by implication. Theoretical Basis. Methods. In order to fully and thoroughly comprehend the essence, role, types and functions of categories, it is necessary to employ rational systemic and dialectic methods, and also semantic analysis. Results. After due consideration of these issues, there was a increased conviction that categories are the most important tools, guidelines, foundations and outcomes of cognitive activity. The importance of categories in scientific research, in ensuring day-to-day life of society, as well as in the development of special knowledge systems and the implementation of specific types of social practice, is high. It is determined by the place of categories in the lexicon of science and social reproduction, in the organization of essential social activities, all of which would be impossible without having a theoretical, political and organizational uniqueness. A more complete and deeper understanding of the place of categories can be found in their origin and etymology, in the very concept of ”category” and in the essence of certain categories. Of great importance is also the typology of categories, as well as the functions and limits of their application. An important result of the study is the conclusion that categories do not ultimately give rise to fundamental contradictions between researchers of various specialisations. On the contrary, good and skilful use of categories makes it possible to gain a full perception of reality and interaction. Discussion and Conclusion. Understanding categories has become an important factor in the development of science and society. These findings present further opportunities for the development of science, technology, and the improvement of social relationships.