HD means high definition. The TV people have adopted that term for HDTV, so be it. I threw a number out there, but should have known better since someone was t

HD means high definition. The TV people have adopted that term for HDTV, so be it. I threw a number out there, but should have known better since someone was to nitpick it. The correct term is PPI (screens) over DPI (printers). Also, PPI is pixels per inch. PPI is not relative to viewing distance. DPI is not relative to viewing distance.[1] An iPhone 4S has 326 PPI. We already have a technically accurate method to measure pixel density, so let's use it. Use bytes to describe data, not Libraries of Congress. Retina is a marketing term. Does phone A had better PPI than phone B? I don't know, is Retina better than Super AMOLED++? Why not just compare technical details instead of resulting in fuzzy marketing word arguments? [1]: DPI does not change with viewing distance, but the closer the viewing distance the higher the DPI needs to be to achieve the same visual effect. A billboard can look the same as a postcard at a much lower DPI because at that distance the human eye can't discern the individual dots.