Price action is how price moved the way it did. It is what you see on a chart.
Supply Demand is what the reason behind price action to do what it did.
In short supply demand zones form the origin of price beginning its journey up or down.
Clever traders buy where they buy-or sell where they sell and they stay ahead of price action by understanding and applying price action causes and effects ahead of its happening.
The video here helps getting it.
What odds favour supply demand shifts?
see ODDS ENHANCERS picture
http://www.youtube.com/watch?v=Um5gDT7whcI
