HDTV is an entirely new enhanced system of both the production and reception of television broadcast signals. They say it gives the viewers a cinema effect. The magic lies in something called the aspect ratio, which is the ratio of width to height of any display. Resolution Our current NTSC standard has a resolution of up to 525 lines. New HDTV has 1125 lines of resolution, providing a sharper image.
Availability There are already many televisions available that are HDTV compatible or HDTV-ready.
Not everything you view on one of these sets will be of HDTV quality, since not all channels are broadcasting HDTV, but when they do, you'll be ready if you've got one. Outside the United States, HDTV has already become a standard. Since it will soon enough become a standard system in America, there are a lot of issues that need to be dealt with. Many countries share the NTSC standard including America. NTSC signals have a resolution of 525 horizontal lines stacked on top of each other.