Let’s look more closely at a trip-planning web site to determine exactly how it allows its users to customize road maps. The application likely makes use of several services provided by distinct servers:

• A gazetteer server provides services to convert the place names into geographic locations;
• A route server provides services to get the road route between the two geographic locations;
• A map server provides services to get a base map on which the route is displayed;
• An overlay server provides a service to overlay the route on the map; and
• A display route server makes use of the services above to convert a road route request into a map displaying the route.