What is LINQ
Language Integrated Query (or LINQ, pronounced “link” for short), is a set of Microsoft® .NET technologies that provide built-in language querying functionality similar to SQL, not only for database access, but for accessing data from any source.
There is no one definition for LINQ, but it aims to solve the problem where we currently use different techniques for manipulating and selecting data from databases versus XML versus object collections; LINQ aims to make our life easier by giving us a coordinated, consistent and efficient syntax from our development environment and by using your one chosen programming language, rather than switching between programming languages.
The current LINQ family of technologies and concepts allows an extensible set of operators that work over objects, SQL data and XML data sources. The generalized architecture of the technology also allows the LINQ concepts to be expanded to almost any data domain or technology, so what LINQ is today will expand in the future.