The data are indexed by state, county, and place FIPS codes.
The data contain information on a wide range of geographic features such as populated places, rivers, mountains, certain buildings, etc. The data provided include geographic coordinates, elevation at the point, population (if applicable), and the FIPS codes for the state and county containing the feature (but not the feature itself).
The system describes the codes and the relationships between different entities, such as the part of relationship between a U.S. state and a county.