WorldCat is a global library catalog, which is maintained by OCLC (Online Computer Library Center). It is the largest and most comprehensive catalog of library collections in the world, containing over 400 million bibliographic records representing materials held by more than 72,000 libraries in 170 countries.
WorldCat allows users to search for and locate books, journals, articles, and other materials held by libraries worldwide, as well as access to digital resources such as e-books, audiobooks, and databases. The catalog includes a wide range of materials, including books, journals, newspapers, manuscripts, maps, music, sound recordings, videos, and more.
Users can search WorldCat by keywords, author, title, subject, ISBN, or other bibliographic data. They can also limit their search by location, language, and format. The WorldCat records include information such as title, author, publication date, ISBN, and summary of contents.
In addition to being a useful tool for researchers and patrons looking for specific materials, WorldCat can also be used by libraries to identify and acquire materials held by other libraries, through interlibrary loan or resource sharing programs.
It’s worth noting that WorldCat is different from the Library of Congress catalog, which is another important catalog but it only lists the collection of the Library of Congress.