According to the Society of American Archivists, archives are "the non-current records of individuals, groups, institutions, and governments that contain information of enduring value." (SAA, 2015). This means that archival records are:
Archival collections are different from library collections which usually contain published materials, most of which are considered secondary sources, not primary sources.
Archival collections are arranged according to two basic principles: Provenance and Original Order.
Both of these concepts ensure that archival records preserve context as well as content.
Provenance and Original Order mean that archival collections are organized differently from library collections. Library collections are usually arranged by subject, with all the information on one subject grouped together. In archival collections, information on a particular subject may be scattered across many different collections.
Archival records are also indexed or cataloged at the box or folder level, not the item level. This means that archival catalogs and finding aids will not tell you the content of or even existence of every piece of paper in the collection. They will only give you a general idea of what is in each box or folder. The rest is for you to discover!