While metamodels are essential to construct an EA in TOGAF, you must use a content model because it is the one that consists of all the definitions. An interviewer who wants to test your knowledge about metamodel and TOGAF metamodelling will try posing such questions to you. The content metamodel is the one that defines all the vital elements within an enterprise architecture. However, you can state a more precise definition, like, "A content metamodel will confine the elements within an enterprise architecture model are interrelated to each other and how each of them is described." A content metamodel is responsible for identifying all the risks and concerns and recognizing the core metamodel entities like the function, actor, business service, data entity, etc.