Difference between lambda and LINQ? [duplicate]

Answer 1

Linq (Language Integrated Query) can use Lambdas (Lambda Expressions) but doesn't have to.

This is Linq:

var a = from b in someList
        where b.Value == something
        select b;

But can be written with a Lambda:

var a = someList.Where(b => b.Value == something);

The Lambda is b => b.Value == something.

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Where as mock.Setup(m => m.SomeOp()).Returns(new Thing()); uses a Lambda (the m => m.SomeOp()), but has nothing to do with Linq.