What is Entity Framework?
ADO.NET Entity Framework is an object-relational mapping (ORM) framework for the .NET Framework. Basically it represents the relational (logical) schema of the data that is stored in a database and presents its conceptual schema to the application.
In relational schema the attribute of the table is hardcoded into application. This is the major disadvantge of this,if you change the schema you also need to change your application.
To avoid this problem, Entity framework is maintaining the mapping of logical schema into the physical schema that defines how the data is structured and stored on the disk. The job of the database system and client side data access mechanisms are shielded from it as the database exposes the data in the way specified by its logical schema.
Microsoft released first version of Entity Framework was included with .NET Framework 3.5
Service Pack 1 and Visual Studio 2008 Service Pack 1,
released on 11 August 2008.
The second version of Entity Framework was released as part of .NET 4.0 on 12th April 2010.
For more details:
http://msdn.microsoft.com/en-us/library/aa697427%28VS.80%29.aspx#ado.netenfrmovw_topic4
