Who's Who is a reference work. It has been published annually in the form of a hardback book since 1849, and has been published online since 1999. It has also been published on CD-ROM. It lists, and gives information on, people from around the world who influence British life. Entries include notable figures from government, politics, academia, business, sport and the arts. Who's Who 2025 is the 177th edition and includes more than 32,500 people. In 2004, the book was described as the United Kingdom's most prominent work of biographical reference. The book is the original Who's Who book and "the pioneer work of its type". The book is an origin of the expression "who's who" used in a wider sense. Source: Wikipedia (en)