A.FortiWeb replies with a HTTP challenge of behalf of the server, the if the user authenticates successfully, FortiWeb allows the request and also includes credentials in the request that it forwards to the web app

B.FortiWeb forwards the HTTP challenge from the server to the client, then monitors the reply, allowing access if the user authenticates successfully

C.FrotiWeb redirects users to a FortiAuthenticator page, then if the user authenticates successfully, FortiGate signals to FortiWeb to allow access to the web app

D.ForitWeb redirects the user to the web app's authentication page