The World Factbook is a reference publication by the CIA that provides information on 267 world entities. It began as a classified publication but is now publicly available online. The Factbook contains information on history, government, economy, and other topics for each location. It draws information from reliable sources like government agencies and is intended for anyone seeking international data. Users can search for statistics on specific countries or global issues. Country profiles display data in categories, fields, and subfields on topics like demographics, military spending, and internet usage.