To illustrate the demultiplexing job, recall the household analogy in the previous
section. Each of the kids is identified by his or her name. When Bill receives a
batch of mail from the mail carrier, he performs a demultiplexing operation by
observing to whom the letters are addressed and then hand delivering the mail to his
brothers and sisters. Ann performs a multiplexing operation when she collects letters
from her brothers and sisters and gives the collected mail to the mail person.