Josh Lovison, content manager for MediaPost, wrote a good article explaining High Definition (HD) TV for us common folk -- both for HD Televisions and HD DVD's. So, here is an edited down copy of his article.

... First, what HD is, and why it doesn't really matter. High Definition is essentially more detail (pixels) included in the picture of your favorite video content. It comes in three popular flavors: 720p, 1080i and 1080p. Generally, you're watching 720p if you watch HDTV, as it deals better with motion; most TVs can't yet show 1080p. To get an idea of how much more detail is in the picture, take a look at this chart. That small little "DV NTSC" box is what Standard Definition (normal TV) would look like if displayed on your computer monitor. Yes, that size. The larger rectangular box labeled HDTV is what 720p would look like. And that really big box you need to scroll around to the edges to view? That's what 1080p would display.

Impressed? You should be. Too bad it doesn't really matter.

The human eye can't see all that detail for most home HD setups. This guy Carleton Bale explains HD online, but most importantly, he made this chart, which shows what a 20/20 eye can see, based on the distance from the screen and the size of the TV. Sit 10 feet from your TV? In order to see the full benefit of just 720p, you need to have a 50-inch TV. However, if your screen is larger than 32 inches, at that distance, you'll see some improvement.

To see the full benefit of 1080p from 10 feet away, you need a 75-inch TV. That said, I watch my TV on a 24-inch monitor from about 8 feet away, and I refuse to watch my TV shows in less than HD, because there's more to the experience than just the detail. HD also has richer colors; the black looks blacker, and the white whiter. But that chart is certainly worth keeping in mind as an anti-buzz.

Second, many people with HDTV aren't watching HD. In my experience, I have yet to see a home HD setup that is actually in HD. In some cases, the people didn't know they needed to subscribe to special HD channels. In others, the TV was on the wrong setting. Or, the cables being used to connect to the TV were the wrong kind. But in all instances, someone had spent the money to buy a HDTV, yet was watching standard definition content on it, which almost always looks worse on an HDTV than a normal TV.

Third, things are only going to get more confusing. To begin, there are two standards for disc distribution of HD content: Blue-Ray and HD DVD. And they are almost exactly the same, but the two don't want to play nice. Worse than that is the confusion the copyright protection scheme put in place: HDCP (High Bandwidth Digital Content Protection).

HDCP requires all devices, from HD-DVD player to Receiver to TV, to be licensed with its technology in order to play HD content. If any of those items aren't, or are hooked up incorrectly, the protected content won't play or will be downgraded to worse than 720p resolutions, at the discretion of the content producer. And unless you bought an HDTV with an HDMI input (the kind that's one cable for both audio and video) within the past 18 months, chances are your TV, even if HD, is considered outdated.

This is also going to apply to digital distribution models. ... Remember, if you download content to your computer, your graphics card and your monitor need to be licensed with HDCP, or that HD content won't play. And unless users bought their hardware in the past six months with this requirement in mind, chances are they're going to need to upgrade.

Why all this insanity? It's about making money.

... The real push for this technology comes from Intel, which pioneered the technology behind it, and the hardware manufacturers. Intel makes a lot of money by requiring that every device obtain a license from them to play content. Hardware manufactures make money when consumers buy a whole new home theater setup (which costs more because of the license fees) in order to play new content.

... Bottom line: users can't really see HD, [most people] generally are set up improperly to watch HD, and unless they are up on the world of digital copyright protection, are likely in the near future to be disallowed HD. ...

If you ... just like to watch HDTV, make sure you purchase your hardware intelligently (in many cases forgoing 1080p buzz), set it up correctly, and support media that doesn't subscribe to restrictive copyright protection schemes. And if you've never watched HD before, go out and give it a try. All the complexity may seem burdensome, but HD's intentions (and quality) are good. Please don't let it be misunderstood.