WBI s APIs provide more power, flexibility and programming simplicity than many of the other approaches. WBI can easily produce both dynamic or static content and allows complex web-based applications to be developed with ease. However the line between proxy and server often becomes blurred in practice. Likewise, many servers can be configured to forward certain types of requests on to other servers for processing. When they do this, they are acting like proxies.
Most web browsers have a configuration option for setting the browser s proxy.
This setting is then used to handle requests that the browser makes. If the setting is left empty, the browser simply contacts the origin server directly. But if the browser is configured to use a proxy, that proxy is contacted for every request that comes from the browser, regardless of the actual origin server specified by the user. Note that this simple explanation has ignored the fact that many browsers can be configured to use different proxies for different types of URLs. The requested origin server is changing all the time as the user browses the web, but the fact that the requests are being handled by a proxy is less obvious.