A catalog is a systematic list or collection of items, often organized in a specific order. It can include products, services, or resources, and is commonly used by businesses, libraries, and educational institutions. Catalogs help users find and access information quickly, making it easier to compare options and make informed decisions. There are various types of catalogs, such as product catalogs for retail items, library catalogs for books and media, and online catalogs for digital resources. Each type serves a unique purpose, but all aim to provide a clear and organized way to present information to users.