Intuition behind Comparative Advantange
A classic example is to consider the question


  Why doesn't Tiger Woods mow his own lawn?


Woods is an excellent golf player. But he also may be excellent at mowing. Still, if he devotes time to mow the lawn he sacrifices time playing golf, in which he is much more productive.

A gardener who is skilled at mowing lawns but not at playing golf sacrifices less in order to mow, so even though Tiger Woods may be better at it (i.e. has an absolute advantage), the gardener has a comparative advantage. Both benefit if the gardener is paid for the time that he mows the lawn by Tiger Woods who in the time he saves can earn more by concentrating on golf.