Digital video compression uses several frame types. Most frequent ones are inter-frames, and those encode the difference from the previous frame — so if you don

Digital video compression uses several frame types. Most frequent ones are inter-frames, and those encode the difference from the previous frame — so if you don't have those previous frames, you can't decode a usable picture. You have to wait for the next intra-frame to be transmitted, which contains a complete picture by itself. Analog video doesn't have that restriction, every single frame is self-sufficient. > Also Teletext worked always fast and was instant. That's not at all how I remember it. I remember it taking anywhere from instant to 15 seconds to load a page.