An archive is an accumulation 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 that person or organization.
Professional archivists and historians generally understand archives to be records that have been naturally and necessarily generated as a product of regular legal, commercial, administrative, or social activities.
They have been metaphorically defined as the secretions of an organism, and are distinguished from documents that have been consciously written or created to communicate a particular message to posterity.
In general, archives consist of records that have been selected for permanent or long term preservation on grounds of their enduring cultural, historical, or evidentiary value.
Archival records are normally unpublished and almost always unique, unlike books or magazines for which many identical copies exist. This means that archives are quite distinct from libraries with regard to their functions and organization, although archival collections can often be found within library buildings.