1.
RTMPdump is the program that actually downloads the video. The problem is that it required a list of parameters that are not easy to get.
2. RTMPsrv is designed to capture these parameters when the video is played through your browser, then invoke RTMPdump. The problem with THIS is that a windows browser cannot be configured to allow RTMPsrv to capture these parameters, because Windows sucks.
3.
RTMPexplorer is designed to overcome the suckiness of Windows and allow RTMPsrv to capture the parameters; and in doing that download the video with RTMPdump.