Online Public Access Catalogue (OPAC) or simply a Library Catalogue is a digital database of materials such as text files, e-books, journals, etc held by a library or group of libraries. Patrons can use the online library cataloguing software to find out any item under control of a library. It displays the query search results in an easy-to-understand format to enable patrons to find digital material quickly.
The globally located library authorities or librarians have the provision to update the catalogue which usually requires a small amount of time.
Information about documents can be searched using powerful search engine according to: