When using archives, it's helpful to know the terminiology. You'll find these terms used in finding aids and other cataloging records.
Definitions are from the Dictionary of Archives Terminology, published by the Society for American Archivists and available online, https://dictionary.archivists.org/index.html
Access: (1) the ability to locate relevant information through the use of catalogs, indexes, finding aids, or other tools (2) the permission to locate and retrieve information for use (consultation or reference) within legally established restrictions of privacy, confidentiality, and security clearance (3) the physical processes of retrieving information from storage media (computing)
Access point: A name, term, phrase, or code used as a heading in a catalog, especially to group related information under that heading. Examples of common access points within catalogs include author, title, and subject
Accession: the materials physically and officially transferred to a repository as a unit at a single time
Appraisal: the process of identifying materials offered to an archives that have sufficient value to be accessioned.
Archival value: the ongoing usefulness or significance of records, based on the administrative, legal, fiscal, evidential, or historical information they contain, justifying their continued preservation
Archivist: (1) a professional with expertise in the management of records of enduring value (2) an individual responsible for records of enduring value
Arrangement: (1) the process of organizing materials with respect to their provenance and original order, to protect their context and to achieve physical or intellectual control over the materials (2) the organization and sequence of items within a collection
Chain of custody: the succession of offices or persons who have held materials from the moment they were created.
Collection: (1) a set of archival or manuscript materials (2) materials assembled by a person, organization, or repository from a variety of sources; an artificial collection (3) (sometimes pl., collections) a thematic aggregation of sets of otherwise unrelated archival materials (4) (also pl., collections) the holdings of a repository, taken as a whole
Container list: part of a finding aid that indicates the range of materials in each box (or other container) in a collection
Description: a set of data crafted to identify and represent an archival resource or component thereof
Extent: A description of the physical quantity of the material described (usually # of linear feet and/or # of boxes)
Finding aid: a description that typically consists of contextual and structural information about an archival resource. Often a finding aid places archival resources in context by consolidating information about the collection, such as acquisition and processing; provenance, including administrative history or biographical note; scope of the collection, including size, subjects, media; organization and arrangement; and an inventory of the series and the folders. Finding aids could also describe a single level or a single item.
Manuscript: (1) a handwritten document (2) an unpublished document
Papers: (1) records created and originally kept by an individual or a family (2) (usually capitalized) used in the title of a set of archival materials to identify these as one created by an individual or a family (3) records on paper considered as physical objects rather than an aggregation of information
Processing: preparing archival materials for use (usually by arrangement and description)
Provenance: information regarding the origins, custody, and ownership of an item or collection
Name Authority file: A compilation of authority records that describe the preferred forms of names used as headings in a catalog, along with cross-references from variant forms of the name. A name authority file often includes a few key facts about the entry to help ensure that the name being checked matches the entity represented by the authority record. For example, a heading for John Smith might note a middle name, birth and death dates, and other details to distinguish one John Smith from another. The authority record might include notes about his works, his nationality, or his occupation to ensure that the heading is applied correctly.
Scope and Content note: A narrative statement summarizing the characteristics of the described materials, the functions and activities that produced them, and the types of information contained therein
Record: information or data created or received by an organization in the course of its activities; organizational record
Record group: a collection of records that share the same provenance or were created in the same administrative unit
Repository: an institution focused on the care and storage of items of continuing value, particularly records
Restriction: limitations on access to or use of materials