In a network environment, a proxy is positioned between the requesting client and the server. The proxy accepts requests from the client and passes them onto the server and brokers the response back to the client.
The Ajax proxy provided with the IBM® WebSphere® Application Server is a reverse proxy. You can install a reverse proxy near one or more servers. Incoming connections through the reverse proxy are forwarded to the requested server. From the clients perspective, the requests originate from the same server, even though the reverse proxy might be forwarding requests to multiple Web servers.
You can use the proxy to broker client requests from multiple domains while using Ajax. JavaScriptTM sandboxing rules prevent the start of network requests to servers from where the JavaScript did not originate. The policy is referred to as the same-origin policy on most major browsers. As an example, if the JavaScript application originated from domain A and attempts to use an XMLHTTPRequest to domain B, then the browser prevents the domain B request. You can use the proxy to broker the request. From the client view, the request originates the same server that the JavaScript originated.