Entity Framework was first released in 2008, Microsoft's primary means of interacting between .NET applications and relational databases. Entity Framework is an Object Relational Mapper (ORM) which is a type of tool that simplifies mapping between objects in your software to the tables and columns of a relational database.
Entity Framework (EF) is an open source ORM framework for ADO.NET which is a part of .NET Framework.
An ORM takes care of creating database connections and executing commands, as well as taking query results and automatically materializing those results as your application objects.
An ORM also helps to keep track of changes to those objects, and when instructed, it will also persist those changes back to the database for you.