LINQ is a set of extensions to the .NET Framework.the expansion of the linq is Language integrated query. The LINQ adds native data queries capabilities to  .NET.
The uniq applicable operations are,


Select
Where
SelectMany
Sum / Min / Max / Average
Aggregate
Join / GroupJoin
OfType
Concat
OrderBy / ThenBy
Take / TakeWhile
Reverse
GroupBy
Distinct
Union / Intersect / Except
SequenceEqual
First / FirstOrDefault / Last / LastOrDefault
Skip / SkipWhile
Single
ElementAt
Any / All / ContainsCount