Hold on a second: HD means a resolution of at least 1280x720. Anything lower than that is at best SD (720x480) but most probably less. I understand we're talkin

Hold on a second: HD means a resolution of at least 1280x720. Anything lower than that is at best SD (720x480) but most probably less. I understand we're talking about online videos where the quality and resolution is clearly lower than what's done in the broadcast industry but the terms used should still mean the same thing. So, overall, very few video sites out there are encoding in HD and especially not YouTube. What DarkShikari is saying is that h.264 is the codec used to encode the video. h.264 can be used for videos for mobile to HD. HD is referring to the pixel resolution of the video. Both are completely independent. I suppose that by "not really based in reality", you mean that most people doing HD are using h.264. That's true but that was not your question.