EDMX file in Entity Framework

The EDMX file stores all things about Entity Data Model in Visual Studio container.
The model is stored in an EDMX file (.edmx extension) and can be viewed and edited in the Entity Framework Designer.
An edmx file is an XML file that has conceptual model,storage model and mapping between these models.
It also renders model graphically.
Step by Step diagram to add EDMX file in Visual Studio 2015:-

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