Content model.

A content model provides a blueprint of different content components or parts that can be used in different ways. The content model allows recurring content parts to be structured into reusable components. The content model is a representation of all the available content types used by an organization, and the different discrete elements of each content type. The content model defines the relationship between elements and content types to one another. For example, many different content types will have a title as an element, while other elements may be specific to a single content type. Some content types have just one element, while other content types have many elements. Content types can incorporate other content types as well. 

These relationships provide simple rules that indicate which component to use, how many to use, and when to use them. A single content element can be used in different contexts (either within different content types or to create variant content types) to support different purposes.