An online public access catalog (OPAC) is a computer-based system for libraries and other information institutions to manage and provide access to their collections. It allows users to search for books, articles, and other materials available in the library’s collection. Through the OPAC interface, users can perform various tasks, such as checking the availability of an item, renewing loans, and placing holds on requested materials. OPACs have significantly improved library users’ experience by making it easier to discover and access information resources.