The mission or purpose of an academic library is to service the students and faculty of its particular institution. This library provides support for all classes and curriculum taught in that college or university. Anytime a project or paper is assigned, students should and can assume that the academic library of their institution can provide the materials, books and journal articles, so that they can complete their research. The mission or purpose of the public library is to service the general public of their local community. Local community can be defined as the taxpaying community that supports the library.
Public libraries have special collections like genealogy, career planning, business planning, etc.
The public library can provide bestsellers, children's programming, tax forms, car prices, home improvement information, etc. The mission or purpose of the school library is to support the school curriculum and service the school population. The library will have a range of resources to support school assignments, plus fiction books for casual reading. The mission or purpose of a special library is to support the research and requests of its specific clientele. Examples of a special library range from corporate libraries, medical libraries, museum libraries, and law libraries.