What is Entity Data Model?

  EDM refers to a set of concepts that describe data structure, regardless of its stored form.

EDM supports a set of primitive data types that define properties in a conceptual model. We need to consider 3 core parts which form the basis for Entity Framework and collectively it is known as Entity Data Model. Following are the three core parts of EDM.

• The Storage Schema Model
• The Conceptual Model
• The Mapping Model

The Storage Schema Model

The Storage Model also called as Storage Schema Definition Layer (SSDL) represents the schematic representation of the backend data store.

The Conceptual Model

The Conceptual Model also called as Conceptual Schema Definition Layer (CSDL) is the real entity model, against which we write our queries.

The Mapping Model

Mapping Layer is just a mapping between the Conceptual model and the Storage model.

The logical schema and its mapping with the physical schema is represented as an EDM.

1. Visual Studio also provides Entity Designer, for visual creation of the EDM and the mapping specification.
2. The output of the tool is the XML file (*.edmx) specifying the schema and the mapping.
3. Edmx file contains Entity Framework metadata artifacts.

Source: https://www.tutorialspoint.com/entity_framework/entity_framework_data_model.htm