Theatre art is a fundamental component of modern culture and requires a detailed analysis of the problems of a set of interrelated concepts, which will reflect the key substantive and functional aspects concerning theatre art. The research relevance is determined by the description of the problems of the conceptual and categorical apparatus of theatrical art for the first time is subjected to a complex structural and semantic analysis, which is necessary to determine the study of ways of forming new terms, which will make it possible to present the system of modern theatrical terminology in a holistic form. The study aims to analyse and describe the contemporary problems of the conceptual and categorical apparatus of theatrical art. General scientific methods of art history were used: method of analysis, comparative analysis, synthesis, analogy, and classification. The article investigates the whole stage space as one of the components in the context of the conceptual categorical apparatus of modern art history. Contemporary theatre art is undergoing an active evolution, with artists striving for innovation, using interactive elements, multimedia technology and art installations to create a deep and rich experience for the audience. An important aspect is to involve the viewer in the experience, where the traditional boundaries between actors and audience are blurred and the viewer becomes an active participant. Theatres also emphasise diversity, aiming to reflect different cultures and identities on stage. However, there are problems with the conceptual and categorical apparatus, requiring the development of new terms to accurately describe contemporary phenomena in theatre. Sarcasm and irony prevail, artists seek new directions, and all this happens in the context of the diversity of theatre traditions, creating challenges in the exchange of experiences between cultures. The materials discussed in this article can be applied by both theorists and practitioners of contemporary art history in their writings and as material for teaching in the educational process when training specialists in the field of contemporary art