A domain model is a high-level, logical view of the concepts and relationships that matter to an organisation — a shared map of the information landscape that cuts across business units, applications, and technical environments. This introductory white paper explains what domain models are for, how to read and construct them using a clear notation derived from UML, and how to enrich them with metadata to support data governance, security policy, integration planning, and project scoping. It is a concise, accessible reference for architects, analysts, and anyone working to establish shared understanding of business information across an enterprise.