Object levels are used by archives to indicate the nature of the records being described. For example, if the records were collected at auctions by someone, those records would be a "collection," as they had been collected. The same person may have a "fonds" as well. Fonds are records that are created by a person, society, company or government entity; things like letters, photographs, minutes, etc.
Definitions of the possible levels:
Fonds: A fonds consists of the whole of documents, regardless of form or medium, created and/or accumulated and used by a particular individual, family or corporate body in the course of that creator’s activities or functions.
Sous-fonds: A sous-fonds is a subdivision of a fonds based on the structure of the creator or the organization of its activity.
Collection: A collection is a grouping of documents of any origin intentionally assembled on the basis of some common characteristic.
Series: A series shall consist of files or records within a fonds arranged systematically or maintained as a unit because they relate to a particular function or subject, result from the same activity, have a particular form, or because of some other relationship arising out of their creation or out of their receipt and use.
Discrete item: A discrete item is an individual item that is without context and is not part of a fonds.
File: A file is both a level of description, and an organized unit of documents, usually within a series, brought together because they relate to the same subject, activity or transaction.
Item: An item is the lowest level of description and the smallest entity within a fonds useful for descriptive purposes.