Simplify the following text for a Grade 11 native English-speaking person.
Original: The World Factbook ( ISSN ; also known as the CIA World Factbook ) is a reference resource produced by the Central Intelligence Agency of the United States with almanac-style information about the countries of the world .
Simplified: The World Factbook , also known as the CIA World Factbook , is a book that contains the Central Intelligence Agency 's information about the world 's countries .