A library is a collection of sources, resources, and services, and the structure in which it is housed; it is organized for use and maintained by a public body, an institution, or a private individual. In the more traditional sense, a library is a collection of books. It can mean the collection, the building or room that houses such a collection, or both. The term "library" has itself acquired a secondary meaning: "a collection of useful material for common use." This sense is used in fields such as computer science, mathematics, statistics, electronics and biology. Libraries often provide a place of silence for studying.