What's the difference you ask? The answer is simple and incontrovertible, experience.

Knowledge is the first level of intellectual achievement in any given subject area. It is gained merely through communication and demonstrated or measured through either written or verbal testing. Is it the starting point however; not the destination. Knowledge is only one ingredient in the recipe for accomplishment. We've all heard the cliché "...knows enough to be dangerous" before and that is the nature of Knowledge. Knowledge alone will not get you anywhere in the "real world". For most of us experimentation follows knowledge and reinforces the terms, concepts and principles that are communicated. Just as a house is much more than four walls learning is a much deeper process than just remembering facts

Understanding is the second level. Understanding is what we gain when we begin to apply the knowledge to a goal of some kind. It is gained most commonly through trial and error and typically requires some reinforcement such as repetition with variation. One can understand one aspect of a problem without even knowing that there might be other aspects to the same problem. For example: a person who has never seen a television could be shown the remote control, learn one button and with a little trial and error, successfully understand how to turn the TV on and off. This understanding is exclusive in that the person would not need to even know that the volume can be changed to understand the power button.