An academic library is a library that is attached to a higher education institution and serves two complementary purposes: to support the curriculum and the research of the university faculty and students. It is unknown how many academic libraries there are worldwide. An academic and research portal maintained by UNESCO links to 3,785 libraries. According to the National Center for Education Statistics, there are an estimated 3,700 academic libraries in the United States. In the past, the material for class readings, intended to supplement lectures as prescribed by the instructor, has been called reserves. Previously before the electronic appliances became available, the reserves were supplied as actual books or as photocopies of appropriate journal articles. Modern academic libraries generally also provide access to electronic resources.

A library is a collection of books, and possibly other materials and media, that is accessible for use by its members and members of allied institutions. Libraries provide physical or digital materials, and may be a physical location, a virtual space, or both. A library's collection normally includes printed materials which may be borrowed, and usually also includes a reference section of publications which may only be utilized inside the premises. Resources such as commercial releases of films, television programmes, other video recordings, radio, music and audio recordings may be available in many formats. These include DVDs, Blu-rays, CDs, cassettes, or other applicable formats such as microform. They may also provide access to information, music or other content held on bibliographic databases.