Unicast or Multicast
1) Streams a video file (not a live video stream from a camera).
2) The client's player first saves the part of the video (not the whole file) and then play it.
3) It is sent via unicast connection, so if the video bitrate is 300Kb/s and there are 100 people watching it, it requires 30 000 Kb/s.
LIVE STREAMING (Multicast):
1) The stream is never saved to the client's hard drive.
2) It is sent via multicast, so if the video bitrate is 300Kb/s and there are 100 people watching it, it still requires only 300 Kb/s from the camera to CDN PoPs