The static campaign is there to allow a fixed map selection that can be tweaked by the scripter. You have the opportunity to (almost) define the order of the appearance of the maps in the campaign.
So the static campaign is only about the map selection - the remaining stuff is the same as the other campaign. But the map selection has a big influence on the campaign progress.
- city: City reference to define the position of the mission
A stage contains several sets that define a timeframe and a mission and ufo set that should appear.