What type of catalog does WorldCat maintain?

WorldCat maintains an online public access catalog (OPAC), which serves as a comprehensive and collaborative database of library materials from institutions all around the world. This catalog allows users to search for books, audio-visual materials, journals, and other resources held in thousands of libraries globally. The online nature of WorldCat's catalog means that it can be accessed remotely, providing convenient access to its extensive listings for anyone seeking library resources.

In contrast, a digital database of unique book editions, a physical inventory of library materials, or a specialized index of historical documents does not accurately describe the broader scope and functionality of WorldCat. An OPAC like WorldCat not only lists physical items but also provides rich metadata and information about their availability, making it a powerful tool for researchers and the general public alike to locate resources across various libraries.