EN
The presentation of the first Polish book dealing exhaustively with the phenomenon of tagging on the Internet. The book is a multi-faceted analysis of folksonomies, i. e. the informal categorization of Web content by its users. The author describes theoretical background of folksonomies and Web 2.0., with several interesting Polish and foreign examples of their use. The book is primarily aimed at library professionals, LIS teachers and students, and can serve as a guidebook to informal classification systems.