The simplistic answer is that they are cramming a lot more information into less bandwidth. Analog TV resolution was 640 × 480 (approximately)[1] where digital

The simplistic answer is that they are cramming a lot more information into less bandwidth. Analog TV resolution was 640 × 480 (approximately)[1] where digital TV is 1920 x 1080 [2]. Digital also aggravates reception issues because it doesn't degrade gracefully. Instead of "snow" and color issues, it goes all blocky and then takes a couple of seconds to resynchronize... if it recovers. The Shannon–Hartley theorem[3] relates the necessary signal-to-noise ratio (S/N) that is required to cram a given amount if information into a given amount of bandwidth. Digital TV uses a lot of compression to reduce the amount of information that has to be crammed through the pipe and extremely sophisticated encoding to cram a bunch of bits into each symbol (baud[4]), but, at the end of the day, you have to have an adequate S/N ratio (good enough reception) to decode the signal. [1] http://en.wikipedia.org/wiki/NTSC http://en.wikipedia.org/wiki/NTSC "Each frame is composed of two fields, each consisting of 262.5 scan lines, for a total of 525 scan lines. 483 scan lines make up the visible raster." [2] http://en.wikipedia.org/wiki/Digital_television http://en.wikipedia.org/wiki/Digital_television [3] http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem [4] http://en.wikipedia.org/wiki/Baud http://en.wikipedia.org/wiki/Baud