WorldCat is a global catalog of library collections that allows users to search for books, articles, and other materials held in libraries worldwide. It connects millions of resources from thousands of libraries, making it easier for people to find what they need, whether it's a rare book or a specific journal article. Users can access WorldCat online to locate items in nearby libraries, check availability, and even request interlibrary loans. This service is invaluable for researchers, students, and anyone looking for information, as it provides a comprehensive view of library holdings across the globe.