The ADO.NET Entity Framework is a set of ORM (Object-Relational-Mapping) tools for the .NET Framework, since version 3.5 SP1.
The ADO.NET Entity Framework (EF) is .NET's Object-Relational Mapping (ORM) tool that enables .NET developers to work with relational data using domain-specific objects. It eliminates the need for most of the data-access code that developers usually need to write. Either natively, or through third-party libraries, it supports most major RDBM products including SQL Server, MySQL, Oracle, PostgreSQL and SQLite. It also supports Microsoft's "LINQ" syntax and lambda-expressions via the LINQ to Entities library.