LINQ to SQL is one of the most widely used implementation of LINQ. It is so common that many developers completely overlooked other implementations of LINQ such as LINQ to DataSet or LINQ to Objects. Although LINQ to SQL is only available for SQL Server databases but it is still using all the features available in the other LINQ implementations. In this tutorial, I will give you brief introduction of LINQ to SQL, DataContext object, Entity classes and Object Relational Designer along with some simple LINQ to SQL queries.