Geography plays an important role in Decennial Census Program activities. It is the framework by which the Census Bureau collects and publishes demographic, social, housing, and economic data. Geography contributes to, and is involved in sampling, data collection, weighting, and data tabulation activities.

The nation is subdivided into two main types of geographic areas, legal and statistical.

Legal areas are defined specifically by law, and include state, local and tribal government units, as well as some specially defined administrative areas like congressional districts. Many, but not all, are represented by elected officials. Example: New York State

Statistical areas are defined directly by the Census Bureau and state, regional or local authorities, and include census tracts and urban areas. The primary purpose of statistical areas is to tabulate and present census data. Example: Metropolitan Statistical area - "Boston-Cambridge-Quincy-MA-NH Metro area"

For more information on Geographic Areas, see Geography Program Glossary.