Common reasons for using map services
ArcGIS Server map services represent a map that you've made available to others on the server. ArcGIS Server map services are designed to work in many Web and intranet scenarios. The same map service may be used in ArcMap by one user, a Web application by another user, Bing Maps by another user, and a mobile application by still another user. Here are some common reasons that you might set up a map service.
Cached map services (those that use a set of pre-created images) are the fastest way to serve maps on the web. This is the way that ArcGIS Online services, Google Maps, Bing Maps, and many other services expose their maps. Although users will just be viewing static pictures of your map, you can supplement a cached map service with find, identify, and query tasks to reach the underlying data. You can also update the cache on a regular basis if your data changes.
Map services are not automatically cached; you need to create the cache after you publish the service. See What is Map Caching? to get started learning about how to set up your map service as a set of cached tiles.
Dynamic maps are drawn at the time they are requested by a user. They are not as fast as cached maps, but they may be appropriate for highly-focused intranet applications and applications that require real-time display of data.
Beginning with ArcGIS Server 9.3.1, a new drawing engine is available that improves dynamic map service performance. When you publish a map service using the Map Service Publishing toolbar in ArcMap, your service will use the new drawing engine.
See Map Authoring Considerations for ArcGIS Server for the best ways to author your map to be served dynamically.
Map services don't always need to display images. You can set up a map service for the purpose of returning a set of features to work with in your application. You retrieve these features through tasks that you add to your application.
For example, you might want to query an ArcGIS Server map service and display the resulting features as graphics in the map. This query could be phrased as "Give me all of the features with 'Delaware' in the name", or, "Give me all of the features longer than 100 kilometers".
If you want to set up a map service to serve features, make sure the Query and Data operations are allowed. See Tuning and configuring services to learn about these operations.
The Open Geospatial Consortium has published specifications for exposing map images (WMS), vector features (WFS), and raster datasets (WCS) on the Web. Some organizations require their geographic data and maps to be available in this way. ArcGIS Server map services can be configured to return images or data conformant to OGC specifications. See the section OGC services to learn more.
KML is a way of representing geographic data and maps through an open XML-based structure. KML is commonly used in geobrowser applications such as ArcGIS Explorer and Google Earth to display map overlays or features, with attributes sometimes available in informational popup windows. All ArcGIS Server map services are, by default, able to return KML. See the section KML support in ArcGIS Server to learn more.
You can configure a map service so that field workers can extract data from the map onto their mobile devices. When you publish the map, you can choose the Mobile Data Access capability, which allows mobile devices to access the map through a web service. See Mobile data services to learn more.
You can publish maps to the server that reference geoprocessing models you've created to automate your GIS analysis. The map can act as a container of source layers for the model, or it can be a canvas for displaying the results.
In order to get access to your models, you need to enable the Geoprocessing capability when you publish the map service. The section Geoprocessing services explains more about publishing your models through a map service.
You can set up a map service to work with distributed geodatabases. If your map document contains layers from a geodatabase, you can enable the Geodata Access capability when you publish the map service. Web clients can load the map service into ArcMap and use the Distributed Geodatabase toolbar for data replication and extraction. See the topic Geodata services to learn more.
You can set up a map service for the purpose of performing network analysis on the server. If your map document contains a network analysis layer, you'll see a Network Analysis capability that you can enable when you publish the service. You'll then have access to network analysis operations when developing applications with ArcGIS Server. You can set up default properties for the analysis in the map document, such as facilities, barriers, and so on. See the topic Network analysis services to get started.
These are just some of the ways that you can use a map service. Through your own use of map services, you're likely to discover other uses. All map services are exposed through SOAP and REST interfaces, in addition to the OGC and KML options listed above, making them usable in many ESRI and non-ESRI applications.