A private library is a library

Library

In a traditional sense, a library is a large collection of books, and can refer to the place in which the collection is housed. Today, the term can refer to any collection, including digital sources, resources, and services...

 under the care of private ownership, as compared to that of a public institution, and is usually only established for the use of a small number of people, or even a single person. As with public libraries, some people use stamps, stickers, or embossing to show ownership of the items. Some people sell their private libraries to established institutions such as the Library of Congress

Library of Congress

The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

, or, as is often the case, bequeath them thereto after death, through a will

Will (law)

A will or testament is a legal declaration by which a person, the testator, names one or more persons to manage his/her estate and provides for the transfer of his/her property at death...

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The earliest libraries belonged to temples or administration bodies, resembled modern archive

Archive

An archive is a collection of historical records, or the physical place they are located. Archives contain primary source documents that have accumulated over the course of an individual or organization's lifetime, and are kept to show the function of an organization...

s, and were usually restricted to nobility, aristocracy, scholars, or theologians.