Multicast or Multicasting is the Internet protocol whereby a single IP address (or host) sends a packet to multiple destinations simultaneously using a single, local 'transmit' operation.
In video streaming, multicast is used as method of broadcasting a video signal to multiple users viewing video simultaneously. Using multicast, the video streaming server does not require as many internal computer resources to broadcast the video as if it used udp or tcp/ip to communicate with each client viewing the video.
