http://www.fedora.info/presentations/cmodel-intro.ppt
An important part of implementing a Fedora repository is modeling different classes or "genre" of digital object that will be created, stored, and managed in the repository. Whether the repository will store images, articles, books, journals, electronic records, or other entities, it is essential that an institution analyze its content, and design Fedora digital objects with care.
In Fedora, the term "content model" refers to a data model or a profile for a particular "genre" of digital object. The content model will typically describe the following:
As of Fedora 3.0, content model definitions formalized in the Fedora system using CModel objects. For more information see "Content Model Architecture ."
They can be used to enable object creation, object validation, service binding, and more. Specifications are under way to introduce an xml-based way to express content model specifications, rules, and constraints. These definitions can be stored in special "content model objects" that can be ingested into Fedora repositories (like BDef and BMech objects). Storing such content model objects is a way to register content model specifications in a Fedora repository. The formalization and registration of content models will be a first step to better enabling advanced object validation, new ways of binding services to objects, and more.