ArcIMS is a system comprised of components needed to host ArcIMS services and to process requests and responses. These components can be spread across one or more machines, allowing for load balancing, scaling to meet demand, and redundancy. The components include the Web server, ArcIMS Application Server, Application Server connectors and Web application developer frameworks, and the ArcIMS Spatial Server. Users access ArcIMS services over the Internet or intranet using clients such as a browser, ArcExplorer - Java Edition, ArcMap, ArcPad, and mobile devices. The following diagram shows the relationship of the different components.

• The Web server handles requests from a client using HyperText Transfer Protocol (HTTP). It forwards a request to the appropriate application and sends a response back to the requesting client.
• The ArcIMS Application Server handles the load distribution of incoming requests. It also catalogs which services are running on which ArcIMS Spatial Servers. Using this information, the Application Server dispatches an incoming request to the appropriate Spatial Server.
• The ArcIMS Application Server connectors and Web application developer frameworks provide a communication pipeline between a Web server or third party application server and the ArcIMS Application Server.
• The ArcIMS Spatial Server hosts services and processes requests. It provides the functional capabilities for accessing and bundling maps and data into the appropriate format before sending the information back to a client.

When an ArcIMS request is made, it is first handled by the Web server, passed through one of the connectors or Web application developer frameworks, and then forwarded to the ArcIMS Application Server. The Application Server, in turn, dispatches the request to an ArcIMS Spatial Server for processing. After the Spatial Server is through processing a request, the response is sent through the same pipeline to the originating client.