Custom Entities

A custom entity is a business entity whose schema is created through the customization tools in the Microsoft Dynamics CRM Web application or by using the Metadata Web service. This feature enables you to provide important extensions to support vertical business requirements. It also makes building on the Microsoft Dynamics CRM platform easier, enabling ISVs, for example, to produce solutions that integrate seamlessly with Microsoft Dynamics CRM.
Custom Entity Life Cycle
Create – The schema is created and an empty form is published.
Update - Schema changes are saved to the metadata but UI changes remain unpublished.
Publish - UI changes are published and are visible in the application.
Delete - Schema changes and the UI is changed immediately, no publish step is needed.
When you create a custom entity using the Web application, you enter the schema name for the entity. This name is used to create the logical name and the filtered view name.

Custom entities also support the following functionality:
You can create forms, views, and reports to expose your new entities in Microsoft Dynamics CRM.
You can publish, export, and import these new entities and their associated forms and views.
You can include these new entities in the dataset that Microsoft Dynamics CRM for Microsoft Office Outlook users can take offline.
You can secure these new entities in the same manner as other Microsoft Dynamics CRM entities.
The security privileges available for organization-owned custom entities are as follows: create, read, write, delete, append, and append to.
The security privileges available for user-owned custom entities are as follows: create, read, write, delete, append, append to, assign, and share.
You can define relationships for custom entities.
Callouts for custom entities function in the same manner as for system entities.
Client-side events function in the same manner as those for system entities.
Custom entities can be extended using the ISV.config file in the same manner as system entities.
The filtered views for custom entities are available to be used in the same manner as for system entities.