When a descendant of TWebApplication receives an HTTP request message, it creates a TWebRequest object to represent the message, and a TWebResponse message to match the request. It then calls HandleRequest, passing those objects as the Request and Response parameters. 

HandleRequest activates the Web module associated with the Web application. It then passes the request and response objects to the dispatcher, so that it can dispatch the request to the appropriate action items. When the dispatcher returns, HandleRequest checks whether the response was handled but not sent, and if not, sends it. Finally, HandleRequest deactivates the data module. 

HandleRequest returns a Boolean value indicating whether the request message was handled and sent. 

ActivateWebModules 

DeactivateWebModules