Feature services are similar to map services, but provide more functionality. Their content can be edited, if the database and map settings support those operations. They display their feature symbology without the need of a legend service. Their symbology can also be modified client-side, by changing their renderer. The URL of a feature service is similar to a map service, except that it ends with FeatureServer, as shown in the following:

http://<GIS-web- server>/arcgis/rest/services/<folder>/<mapname>/FeatureServer

The feature service differs first and foremost in its capabilities. Apart from allowing you to query data, feature service capabilities allow the user to create, update, and/or delete records. Those familiar with CRUD operations will recognize those words as the C, U, and D in CRUD (the R stands for read, which is what happens when you query for results). The capabilities include editing if create, update, or delete are allowed. Also, if the...