ESRI provides a variety of tools, or task-based services, that perform a function, such as geocoding, routing, or spatial query. These ready-to-use services can be accessed with any ArcGIS application. ArcGIS Online services are always available on the Web, so users with Internet access can use these services at any time.
Online tools for geocoding, routing, and spatial query are built into ArcGIS Desktop, ArcGIS Explorer, and ArcGIS Server. See the section on geocoding in ArcGIS Desktop Help, the ArcGIS Server Resource Center, and ArcGIS Explorer Resource Center for details.
The ArcGIS Online task server provides address locators and routing services for Europe and North America, a world places locator, and a geometry service. The address locator services support single address, reverse, and batch geocoding. The routing services support point-to-point and optimized routing.
These free tools are available to use in your ArcGIS applications. For external commercial use of ArcGIS Online task services, you must purchase a subscription.
Learn more about these tools using the ArcGIS Services Directory for the task server:
http://tasks.arcgisonline.com/arcgis/rest/services
For information on using the locators with your application, see Using free geocoding tasks on the task server.
For information on using a services subscription, see the appropriate section:
The ArcGIS Online sample servers provide sample mapping and geoprocessing services. Use these samples to learn how to set up your own services and how to discover and use services hosted by other users.
You can browse the GIS services available on these servers using ArcGIS Services Directory. The following links take you to the ArcGIS Services Directory for these sample servers:
http://sampleserver1.arcgisonline.com/arcgis/rest/services
http://sampleserver2.arcgisonline.com/arcgis/rest/services
You can post feedback about the sample services on the ArcGIS Online Forum.