Value describes the worth of individuals in themselves or in the positions which they hold.
Role refers to that position.
A role carries with it certain expectations and limitations the president can do some things which the vice president cannot, and vice versa. Roles bring authority and, unfortunately because they do, status. Ah, there s the rub. Status and value are co-mingled in most of our minds. But if our value is not in what we do but in who or whose we are, then status and value can be distinguished and separated.