The ENTITY Data Model (EDM) USES three key concepts to describe the structure of data: entity type, ASSOCIATION type, and property. These are the most important concepts in describing the structure of data in any implementation of the EDM.

1. Entity Type: The entity type is the fundamental building block for describing the structure of data with the Entity Data Model. In a conceptual model, entity types are CONSTRUCTED from properties and describe the structure of top-level concepts, such as a customers and orders in a business application.

2. Association Type: An association type (also called an association) is the fundamental building block for describing relationships in the Entity Data Model. In a conceptual model, an association represents a relationship between two entity types (such as Customer and Order).

3. Property: Entity types contain properties that define their structure and characteristics. For example, a Customer entity type may have properties such as CustomerId, Name, and Address.

The Entity Data Model (EDM) uses three key concepts to describe the structure of data: entity type, association type, and property. These are the most important concepts in describing the structure of data in any implementation of the EDM.

1. Entity Type: The entity type is the fundamental building block for describing the structure of data with the Entity Data Model. In a conceptual model, entity types are constructed from properties and describe the structure of top-level concepts, such as a customers and orders in a business application.

2. Association Type: An association type (also called an association) is the fundamental building block for describing relationships in the Entity Data Model. In a conceptual model, an association represents a relationship between two entity types (such as Customer and Order).

3. Property: Entity types contain properties that define their structure and characteristics. For example, a Customer entity type may have properties such as CustomerId, Name, and Address.