The ArchiMate approach can be contrasted with the original approach in UML, which we described in Chap. 2. In this approach, semantics was explicitly left out of the program. People who used the models could develop semantics for them, but a general semantics was not supplied. This approach also stemmed from the origins of UML as a combination of three existing notations that did not have formal semantics. Hence, the focus of UML was and is on notation, i.e., syntax, and not on semantics. Although some of the diagrams of the more recent versions of UML have a formal semantics (see, e.g., the token-based Petrinet-like semantics of activity diagrams in UML 2), there is no overall semantics for the entire language.