In simple terms, latency is the difference in time between one views a video frame and the time when the viewed video frame was sent from the source camera. This time can be in a couple of milliseconds to a couple of seconds based on the network congestion in the route from the source to destination. WebRTC is designed to keep the latency < 1second (~50ms to 500ms) so that it can be used for real time scenarios like video conferencing / interactive live broadcasting etc.