Difference between as and is in C#

as	is
Is Operator is used to check the Compatibility of an Object with a given Type and it returns the result as a Boolean (True or false).	As Operator is used for Casting of Object to a given Type or a Class.
Ex: if (someObject is StringBuilder) ...	Ex: object x = 5; // int y = x as int; // not allowed becoz of int : value type int? y = x as int?; // allowed becoz of nullable type Ex.          Student s = obj as Student;                    is equivalent to: Student s = obj is Student ? (Student)obj : (Student)null;
	as operator should be used with Reference Type or nullable type