Lambda expressions are part of .Net 3.0. They are used extensively in Linq, but they can also be used on their own. With Lambda expressions, filtering and sorting Lists has become a lot easier. I'm going to filter and sort Lists of Employee objects: public class Employee { public string FirstName { set ; get ;} public string LastName { set ; get ;} public decimal Salary { set ; get ;} public bool IsManager { set ; get ;} } FindAll( ) Suppose I have a List of Employees, and I want to find all the managers. At one point I would have written code like this: List < Employee > managers = new List< Employee >( ); foreach ( Employee employee in employees) { if (employee.IsManager == true ) managers.Add(employee); } The new syntax with Lambda expressions is clean and simple: List < Employee > managers = employees.FindAll(employee => employee.IsManager == true ); Note that the term "employee