Documentum uses an object-oriented model to store information within the repository. Everything stored in the repository participates in this object model in some way. For example, a user, a document, and a folder are all represented as objects. An object stores data in its properties and has methods that can be used to interact with the object.
A content item stored in the repository has an associated object to store its metadata. For example, a document stored in the repository may have its title, subject, and keywords stored in the associated object. However, note that objects can exist in the repository without an associated content item. Such objects are sometimes referred to as contentless objects. For example, a user object or a permission set object does not have any associated content.