RTMP Server, how it works
The server must be set up with a media server like Adobe or Red5, but at RTMP Server we use the Wowza streaming engine, for the RTMP live streaming.
The video stream connects to the RTMP installed on the server, the video stream could be a laptop with software installed, this software is an encoder, there are a number of them, OBS Studio, it is free and can be used for Mac, windows or even LINUX computers. OBS is a very good and stable encoder.
On the encoder you enter the server RTMP, which would be something like this:
rtmp://server_IP/live/stream_name
Then you connect and start the broadcast. this stream will go directly to the RTMP server and you can now set up a player for your users, if you using an RTMP player, you will need to use a flash player, but by using Wowza Streaming Engine on the RTMP server, it converts the stream to a HLS protocol, which can be used on many other platforms as well, like smartphones and HTML5 players. Although the HLS has the latency issue because of the flash player at the end of live it is nearly impossible not to use it. Nowadays, with a good configuration, you can reduce the latency to 3 or 4 seconds.
So we have, YOU on your laptop with a camera and an encoder >>> your internet connection and the RTMP Server connection >>> and finally the player on your site broadcasting your live event. Or your video files.