A world record is usually the best global performance ever recorded and officially verified in a specific skill or sport. The book Guinness World Records collates and publishes notable records of all types, from first and best to worst human achievements, to extremes in the natural world and beyond. The website RecordSetter has begun to take on the same territory, but with a more inclusive policy, as users submit videos of record attempts in order to try to receive a world record. The website challengers.guinnessworldrecords.com is similar to RecordSetter, as the record attempts are judged by Guinness World Records adjudicators, but the records to attempt are provided beforehand.