Pick lists for parameters that are created in Crystal Reports are static lists. The contents of the pick list does not change unless list of default values is manually changed in the crystal report.
Ripplestone allows the user to use a query to populate a pick list. This way, the pick list always accurately reflects the contents of the database. For example, if you have a parameter for customer and a new customer is added, the new customer will automatically be present in the pick list with Dynamic Pick Lists.