Types of Entities in CRM:
· System Entity:System entities are used by Microsoft Dynamics CRM to handle all internal processes, such as workflows and asynchronous jobs. You cannot delete or customize system entities.
· Business Entity:Business entities are part of the Microsoft Dynamics CRM default installation and they appear in the customization user interface. An account, contact, and letter are examples of business entities
· Custom Entity: After installation, you can add custom entities to Microsoft Dynamics CRM to address specific business needs of the organization. In a Microsoft Dynamics CRM Solution, you can set business and custom entities and attributes to be either customizable or non-customizable.