ans 3 What is High Definition?
High-definition television (HDTV) is a digital television broadcasting system with greater resolution than traditional television systems (NTSC, SECAM, PAL). HDTV is digitally broadcast, because digital television (DTV) requires less bandwidth if sufficient video compression is used. HDTV technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television companies. High-definition television (HDTV) yields a better-quality image than does standard television, because it has a greater number of lines of resolution. Because the signal is a digital signal, it produces neither a snowy nor pale image from a weak signal or signal interference effects, such as herringbone patterns, or vertical rolling. Image colors are more realistic, because of the greater bandwidth. The visual information is some 2-5 times sharper because the gaps between the scan lines are narrower or invisible to the naked eye. Television content photographed and preserved
