Think of the water hose analogy. High definition resolution is mainly 1920x1080 or 1280x720 pixels. In order to provide information about all those pixels, data must be sent to the tv or from the camera (thats the water flowing down the hose).

In general, the faster the data (or water) the more information and the higher the picture quality. Bandwidth is just as important as screen resolution.

The HD signals in our home cables boxes may be around 5 MBps. A Blu-ray DVD can be as high as 8 MBps. So a Blu-ray will generally look better than the home HD cable, especially with fast motion, water, flashing lights, etc. Video bandwidth directly from a pro camera sensor (called the HD-SDI spec) runs around 185 MBps! Pro cameras record around 100-150 MBps, semi-pro cameras record around 35-50 MBps.

One of the twists in all this is that quality vs bandwidth is also effected by the compression scheme used. The new HD bullet cams coming out are using the latest compression scheme called H264 (aka AVC, aka MPEG4 Part 10) running between 1 and 2 MBps. Pretty low, but for $300 not bad at all.

Next time your looking at HD tv's, ask what signal they are feeding them with. Our Sears was using a standard def signal from VCRs that was up-convertered to HD. I think Best Buy was using an HD signal. If your looking to compare TV's make sure your seeing an HD signal!

Bandwidth may be listed as MBps or Mbps (big B vs little b). Big B is byte, little b is bit. 1 Byte = 8 bits (1 MBps = 8 Mbps). Sales guys love using Mbps because is sounds higher.