A shared service is a service that is used by multiple functional domains within an enterprise. For example, consumers in the CRM area, the Sales and Marketing area and the Risk Management area might each need access to customer data. Instead of giving these systems direct access to the data service for the customer database, you virtualize the service and give these consumers access to the virtual service (or virtual services). Virtualizing the service gives you greater control over the interface that is exposed to these consumers, enables you to accommodate differences among the consumers by applying different run-time policies and/or processing steps to them and also gives you the flexibility to make modifications to the native service without impacting existing consumers.