You listen for feeling, for meaning. You listen for behavior. You use your right brain as well as your left. You sense, you intuit, you feel. Simply defined, it means that the whole is greater than the sum of its parts.
Covey goes on to discuss synergy in the classroom and synergy in business.
To be effective, The Seven Habits of Highly Effective People emphasizes that we must value the differences between people and how they view the world. That difference can be used as a source of insight. And the key to valuing those differences is to realize that all people see the world, not as it is, but as they are. Just as a machine will wear out quickly if not properly maintained, the same is true for your own personal productivity. You must take care of yourself.