A librarian is an information professional traine in library and information science, which is the organization and management of information services or materials for those with information needs. Typically, librarians work in a public or college library, an elementary- or secondary-school media center, a library within a company, or another information-provision agency. Some librarians are independent entrepreneurs working as information specialists, catalogers, indexers and other professional, specialized capacities. Librarians may be categorized as a public, school, correctional, special, independent or academic librarian.