Language Integrated Query (LINQ) is a great tool shipped with .net framework 3.5. With LINQ you can achieve a lot more functionality and save a lot of your development time.
What LINQ support?
LINQ to SQL Server: With LINQ you can directly connect to SQL server and write down your queries in C#. When you use LINQ to SQL classes, LINQ will automatically generate classes for your tables in the SQL server.
LINQ to XML: With LINQ to XML you can achieve XML programming in .Net framework.
LINQ to Dataset: With LINQ to Dataset you can connect LINQ to ADO.Net Databases
LINQ to Objects: With QINQ to Objects you can achieve any query on the collection of objects. This can help you to avoid loop for multiple conditions over a collection. You can use LINQ to Objects over Array, List etc.
Next article will be on basic LINQ queries.