A librarian, a title which may take a variety of forms, is an individual employed in a professional position within a library who is tasked with the responsibility of providing or maintaining the library's services.
The term may refer to a wide range of individuals employed by libraries, but is usually synonymous with library director. Within the information profession the title 'librarian' is generally regarded as a position requiring a professional qualification such as a Masters or MLS degree from an accredited institute of higher education. Departments within such institutions are often referred to as library schools.
Positions which do not require a qualification are usually regarded as 'non professional', or clerical, and might include job titles such as Library Assistant.
"A professionally trained person responsible for the care of a library and its contents, including the selection, processing, and organization of materials and the delivery of information, instruction, and loan services to meet the needs of its users. In the online environment, the role of the librarian is to manage and mediate access to information that may exist only in electronic form."
- Online Dictionary for Library and Information Science (ODLIS), http://lu.com/odlis/odlis_l.cfm (Accessed 09 July 2007)