Manuscripts and archives are documents produced by organisations or individuals in the course of their activities, and preserved because of their continuing value. Unlike published material, they usually exist in one copy only, and are therefore unique and irreplaceable.
Some examples: letters, notes, diaries, literary drafts, financial records, minutes, reports.
Personal papers of individuals and groups are usually held in manuscript libraries.
Records created by an organisation (especially government organisations) are usually held in archives.
The terms “manuscripts”, “archives”, “papers” and “records” are sometimes used interchangeably. The term “archive” might refer to a collection of papers, or the building that houses them.