Dynamic pricing involves adjusting prices as patterns of demand unfold, raising prices and/or increasing the amount of inventory at particular prices when demand is strong.  Some organisations also use dynamic pricing to reduce prices to stimulate sales when there is strong demand at lower prices, but little demand at higher prices.  In either case, planning your changes in advance is key to a successful strategy, but more importantly a strategy focused on dynamic pricing alone misses much of the potential opportunity to be realised from pricing.