A rural area is typically characterized by a low population density and distance from urban centers. Rural areas often have a strong economic base in agriculture, natural resource management, and small-scale industries. The definition of a rural area varies depending on factors such as location, government policies, and cultural perceptions. The U.S. Department of Agriculture's Economic Research Service (ERS) classifies the 3,142 counties in the U.S. into 9 rurality categories.  These Rural-Urban Continuum Codes are based on whether a county is located in a metropolitan or non-metropolitan area (using Office of Management and Budget's 2013 statistical definitions). After differentiating counties by metropolitan/non-metropolitan areas, the Codes define counties by population size and proximity to urban areas. A "rural" county is one with a code of 4 or higher. The 3,142 counties cluster into 625 distinct "commuting zones." Recognizing that people often cross county lines to live, work, and commute, the U.S. Department of Agriculture's ERS uses U.S. Census Bureau's journey-to-work data to measure the integration of social and economic activity between counties.

A Rural-Serving Institution (RSI) is a postsecondary institution primarily located in a rural area. RSIs are typically the main or even sole access point for postsecondary education in their community and often the largest employer. RSIs contribute to the educational and economic well-being of rural regions, providing educational opportunities, support services, and outreach programs tailored to meet the needs of rural learners, families, businesses, and the community.  In 2021, the Alliance for Research on Regional Colleges developed a tool to more accurately define RSIs. The tool measures “rural indicators” (e.g., institution’s county rural classification, population size, distance from a metro area). A resulting score above a specific level classifies the institution as an RSI. Using this method, AARC identified 1,087 RSIs in the U.S.— 33% of all private, four-year institutions; 46% of all public, four-year institutions, and more than half of all public, two-year colleges. Roughly one-third of Historically Black Colleges and Universities are RSIs, 18% are High Hispanic-enrolling institutions, 93% are Tribal Colleges and Universities, and 94% are High Native-enrolling (nontribal) institutions.