Flex offers support for Webservices, raw HTTP services and RemoteObject services for handling RPCs. The main difference between these lies in the access point and the semantics of the transaction. While HTTP Requests and Webservices are calls made directly to given URL, the RemoteObject services involves connection to a remote object gateway. The HTTP services just go about in raw HTTP format while the WebServices use the SOAP protocol for communications. The RemoteObject services on the other hand rely on the Action Message Format.