When the Web server application creates a TWebRequest descended object for an incoming HTTP request message, it also creates a corresponding object descended from TWebResponse to represent the response message that will be sent in return. For example, in NSAPI and ISAPI applications, the response message is encapsulated by a TISAPIResponse object, and Console CGI applications use TCGIResponse objects. 

The action items that generate the response to a Web client request fill in the properties of the response object. In some cases, this may be as simple as returning an error code or redirecting the request to another URI. In other cases, this may involve complicated calculations that require the action item to fetch information from other sources and assemble it into a finished form. Most request messages require some response, even if it is only the acknowledgment that a requested action was carried out. 

Responding to HTTP requests involves

• Filling in the response header
• Setting the response content
• Sending the response