The HTTP(s) protocol is supported and used for various things.  Primarily the [WebInterface] uses the port.  However, its also used for [WebDAV] and for Remote Administration with a full GUI.  HTTP(s) is also used for tunneling FTP to make it secure, and to accelerate file transfers in the [WebInterface] with the integrated [CrushTunnel|High Speed File Transfer] as part of the high speed file transfers.