Difference Flex/Flash NetConnection and Consumer/Producer

What's the difference between a NetConnection and Consumer/Producer in Flex? It seems that they both use RTMP but C开发者_JS百科onsumer/Producer uses Channels and NetConnection does not. Does the Consumer/Producer uses a NetConnection underneath?

NetConnection is a low-level Flash Player class that enables bidirectional communication between the Flash Player and a server. Both the RMI (remote objects) and Messaging (producer/consumer) implementations use NetConnection in their channels to do the actual communication to and from the server.