IPTV (Internet Protocol television) is the delivery of programming by video streaming. In traditional television delivery, all programming is broadcast simultaneously. The available program signals flow downstream and the viewer selects which program he wants to watch by changing the channel.
IPTV, by contrast, sends only one program at a time. Content remains on the service provider’s network and only the program the customer selects is sent to the home. When a viewer changes the channel, a new stream is transmitted from the provider’s server directly to the viewer. Like cable TV, IPTV requires a set-top box.