Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language.
LINQ is a technique used to retrieve data from any object that implements the IEnumerable<T> interface. In LINQ, arrays, collections, relational data, and XML are all potential data sources and we can query over it to get only those data that meets our criteria and all is done using C#.
Advantages of LINQ
Unifies the way of accessing data from different data sources.
Compile-time checking of all queries, reduces run-time errors.
Can be applied in any project layer(UI/Business/Data).
Extensive Intellisence/Debugging support.
Queries can be dynamically.
Tables are automatically created into class.
Columns are automatically created into properties.
Relationship are automatically appeaded to classes.
Lambda expressions are awesome.
Data is easy to setup and use.
With LINQ you just need to perform three distinct actions.