Guinness World Records, known until 2000 as The Guinness Book of Records (and in previous U.S. editions as The Guinness Book of World Records), is a reference book published annually, containing a collection of world records, both human achievements and the extremes of the natural world. The book itself holds a world record, as the best-selling copyrighted book series of all time. It is also one of the most frequently stolen books from public libraries in the United States.
The franchise has extended beyond print to include television series and museums. The popularity of the franchise has resulted in Guinness World Records becoming the primary international authority on the cataloguing and verification of a huge number of world records – the organization employs official record adjudicators authorized to verify the setting and breaking of records.