Library science, or Library and Information Science (LIS), is the professional knowledge and skill with which recorded information is selected, acquired, organized, and utilized to meet the needs of a community of library users. Usually taught in a professional library school which grants the post-baccalaureate degree of M.L.S. (Master of Library Science) or M.L.I.S. (Master of Library and Information Science).
A few community colleges and four-year institutions will offer Associates of Science in library science or library technology. Very rarely will you find a Bachelors in Library Science. These programs generally train the library paraprofessionals such as Circulation staff, technical services staff, catalogers, library assistants, etc.
Applied library science is called librarianship.