A slide library is a library that houses a collection of photographic slides, either as a part of a larger library or photo archive, or standing alone within a larger organization, such as an academic department of a college or university, a museum, or a corporation. Typically, a "slide library" contains slides depicting artwork, architecture, or cultural objects, and is typically used for the study, teaching, and documentation of art history, architectural history, and visual culture. Other academic disciplines, such as biology and other sciences, also maintain image collections akin to slide libraries. Corporations may also have image libraries to maintain and document their publications and history. Increasingly, these types of libraries are known as "Visual Resources Collections," as they may be responsible for all "visual" materials for the study of a subject and include still and moving images in a variety of physical and virtual formats. They may contain:

• 35mm slides
• lantern slides
• mounted study photographs
• born digital images
• 35mm, 8mm film

Many educational institutions have changed the names of their slide libraries over the years, to a variety of titles like Visual Resources Center, Imaging & AV Center, Digital Collections Center, etc. The titles and duties of slide librarians have therefore expanded greatly. As keepers of these important historical images, visual resources librarians have continuously cataloged and inventoried slide collections, circulated them to faculty for teaching, and more recently, digitized slides and placed them online via content management systems.