Abstract: The development of the social sphere is becoming an urgent issue and requires constant monitoring and rapid and complex decision-making in the face of funding shortages and growing challenges. An important aspect is a thorough study of the basic theoretical concepts and the formation of the categorical apparatus of the social sphere.

The article examines the scientific approaches to defining the essence of the social sphere, and highlights its main structural elements which are in constant interaction and mutual influence, forming a complex adaptive system capable of responding to external challenges and transforming in accordance with the needs of society. The generalized characterization of scientific approaches demonstrates the multidimensionality and interdisciplinarity of research on this phenomenon. The analysis of publication activity in the Scopus database using the keywords «social sphere» shows a steady trend of increasing scientific interest in this issue. The study identified the characteristic stages of the evolution of publication activity. The geographical distribution of publications demonstrates the global nature of research on this issue. The analysis of the sectoral distribution of publications confirms the interdisciplinary nature of social science research.

The article schematically presents the complex structure of the categorical apparatus of the social sphere. The scheme demonstrates the hierarchical organization of the conceptual apparatus, where the central place is occupied by the basic category «social sphere», from which four main groups of categories are derived, revealing various aspects of its essence and functioning. Particular attention is paid to the five-level structure of the social sphere, which demonstrates its multilayered organization. Modern categories of social sector development are presented through transformational aspects and key challenges The key characteristics of the social sphere reveal its essential features: complexity and dynamism of life processes, dual nature of services, ability to reflect the level of socio-economic development of society, multi-level structure with interdependent components and high level of adaptability. Such a conceptual model creates a theoretical and methodological basis for a comprehensive study of the social sphere as a multidimensional social phenomenon that is evolving in the context of modern global transformations.