Returns a subset of items which the specified predicate is true for them.
List<string> trees = new List<string>{ "Oak", "Birch", "Beech", "Elm", "Hazel", "Maple" };
// Select all trees with name of length 3
var shortTrees = trees.Where(tree => tree.Length == 3); // Oak, Elm
var shortTrees = from tree in trees
where tree.Length == 3
select tree; // Oak, Elm