RTMP is a protocol used by the Flash Player to deliver real time objects, video, and audio to clients using a binary TCP connection or polling HTTP tunnel.
The protocol is a container for data packets which may be AMF or raw audio/video data like found in the flv.
A single connection is capable of multiplexing many net streams using different channels. Within these channels packets are split up into fixed size body chunks.
RTMPT basically is a HTTP wrapper around the RTMP protocol that is sent using POST requests from the client to the server. Because of the non-persistent nature of HTTP connections, RTMPT requires the clients to poll for updates periodically in order to get notified about events that are generated by the server or other clients.