HDTV is a vastly improved method of broadcasting television shows and watching entertainment media. It is a byproduct of the digital age in electronics. By converting the picture and sound in digital format, great improvements have been made in the quality of the viewing experience in recent years. We are now able to watch digitally produced movies and programs by DVD and enjoy a much richer picture quality and sound that can even begin to rival movie theaters, however on a much smaller scale.
There are actually several improvements to TV viewing that have been made available in the HDTV standard and perhaps the most obvious is the display itself. Older televisions could only display a TV picture that consisted of 525 lines on the screen. Each line had about 500 pixels of information to show, so that basically adds up to 525 X 500 resolution. Just think on the fact that the most basic of computer displays operate at 640 X 480 resolution and you can begin to see why such an antiquated technology for television viewing needed to be changed.
But there have been even more improvements to the resolution factor in HDTV. Consider that standard televisions may have 525 lines of information to display on the screen but they usually displayed that information on every other line at a time. Every 1/60 of a second it would display first all of the even numbered lines on the screen, and then change to display the odd numbered lines. And this happens over and over again. Because it happens so fast, your brain makes the adjustment for the alternating information and assembles the picture as one piece. This process is called interlacing in standard TV.
In HDTV the number of lines displayed on the screen is greatly enhanced, up to 1080 instead of 525, and the number of pixels on the sreen is up to 10X the number of those found in standard television. In addition, there are many HDTV monitors that can display every line on the screen every 1/60 of a second without interlacing them at all, and this is called "progressive scan". So adding it up, you can have up to 10 times the resolution being displayed in a much smoother viewing format. It's very easy then, to see why so many people are favorably impressed when they see the real capabilities of a broadcast or show being displayed on a high quality HDTV television set. As broadcasting in HDTV format becomes widely adopted in the near future, you will truly wonder how you ever watched television without it.