The main building block for DQS is the Knowledge Base. Knowledge Bases can be created on business scope basis, and there might be one or more domains under each Knowledge Base. Some of these domains might be related to each other and be considered as a composite domain. For example, a Knowledge Base can be set as address data, and domains can be country, city, and address line. And a composite domain named full address might contain all of those domains. In this section, you will see how to create and manage Knowledge Bases, domains, and composite domains.