A content model is defined in its entirety as a single XML document that must comply with the content metamodel XSD schema provided by the Alfresco content repository. Each model contains a set of related and coherent definitions and is deployed as a unit.
You can deploy several content models to the content repository. Definitions in one content model may depend on definitions in another content model, allowing for the sharing of definitions.
There are two approaches to deploying a content model into the content repository: