Many enterprise architecture frameworks make use of domains. In this session we discuss the use and benefit of architecture domains. We first take a look at the four most common ones, examining each to understand their purpose. From this, we move on to explore the evolution of enterprise architecture with the emergence of other domains. With the definition and adoption of others, we are able to appreciate how architecture practices are meeting the new challenges they face. The session concludes by considering recommended approaches for working with enterprise architecture domains.