An OPAC, or Online Public Access Catalog, is a digital system that allows users to search for and locate library materials. It provides access to a library's collection, including books, journals, and other resources, through a user-friendly interface. Users can search by title, author, subject, or keyword, making it easier to find specific items. OPACs are commonly used in libraries worldwide, enhancing the efficiency of information retrieval. They often include features like availability status, location within the library, and links to digital resources. This technology has transformed how patrons interact with library collections, making information more accessible.