The Language-Integrated Query (LINQ) framework is what mostly changes the programming technique in the .NET world. LINQ is a framework that lives within the .NET language and helps us create complex queries against any data source, such as in-memory objects using the LINQ to object-provider or against an Entity Framework database using the LINQ to entities provider.

Almost anything that is enumerable in the world has its own provider within a simplified index, as shown at the following link:

http://blogs.msdn.com/b/charlie/archive/2008/02/28/link-to-everything-a-list-of-linq-providers.aspx

Any iteration for the for or foreach statements is now made with LINQ. The same is made against any relational database accessed by an O/RM or any non-relational database too. LINQ has its own pseudo SQL language that is accessible within any .NET language. Here is a LINQ statement example:

var query = from i in items
            where i >= 100
            orderby i descending...