The CIA (Central Intelligence Agency) World Factbook is an incredible resource about the countries of the world. It's free and available online and you can also download a copy for offline viewing and access. Older versions (back to 2000) are also available, which can be good for history teachers looking for older information.
The site has information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 267 world entities. The Reference tab includes: maps of the major world regions, as well as Flags of the World, a Physical Map of the World, a Political Map of the World, and a Standard Time Zones of the World map.. It's a great resource to find out information about the countries of the world and the CIA is constantly updating it.
Check it out and share it with your students. https://www.cia.gov/library/publications/the-world-factbook/