Microsoft CRM 2011 Entity Model

http://msdn.microsoft.com/en-us/library/gg334400.aspx

Model Your Business Data With Microsoft Dynamics CRM

Microsoft Dynamics CRM 2011 and Microsoft Dynamics CRM Online provide a robust and customizable data model that uses entities to define the data tracked in the system. This section describes the out-of-the-box entities that correspond to the areas shown in the Web application. These entities are defined by metadata. For more information about how to customize entities, see Extend the Metadata Model for Microsoft Dynamics CRM.