Library of Congress Subject Headings (LCSH) is a standardized set of terms and phrases that are used to describe and classify the subjects of books and other materials in the collections of the Library of Congress and many other libraries around the world. LCSH is used to assign subject headings to books and other materials and to organize them in the library’s catalog so that users can find and access relevant materials more easily.
The LCSH system includes over 1.5 million subject headings and is updated regularly to reflect changes in knowledge and research. The subject headings are arranged alphabetically and are hierarchical, meaning that more specific terms are listed under more general terms. LCSH is used to describe a wide range of subjects, including literature, history, science, and technology, and they are intended to be as comprehensive and inclusive as possible.
In addition to helping users find and access materials, LCSH is also used to facilitate the sharing of information between libraries and to support the development of library collections.