Live broadcast is a feature that enables the coding iPad (the server) to transmit stats as they are coded to other devices (the clients) connecting to it. This is very useful when the coder cannot be on the bench during the match and is still able to send stats as it happens to coaches on the bench. Stats can also be transmitted to AppleWatches via the free AOC VBStats Client app.
In theory there can be as many as 16 clients connected to the server. However the more devices connecting to the server the less reliable the transmission will be.
The devices can be connected to each other using Bluetooth but for greater reliability they should be connected to the same wifi router. Internet connection is not required during a live broadcast.