The article discusses the methodological approaches to the definition of fundamental concepts in the regional economy. The authors investigate the essence of the concepts of territory and region and determine the main characteristics of the region as parts of a territory with more or less homogeneous natural conditions, specific economic, demographic, and historical conditions, on which a certain complex of industries, production and social infrastructure functionate. The study reveals some approaches (concepts) to the integrated development of regions. From an economic point of view, a region is defined as a part of a country's territory, which is characterized by a geographical unit and economic homogeneity, an inter-regional division of labor and product orientation, and is formed around one or more industrial centers. Since a region forms an intermediate or hybrid spatial unit between a nation and its citizens, the regional theory of economic growth uses such elements as macroeconomic growth policies and the theory of individual well-being.