HD – not since compassionate conservatism has a term so overused been so little understood. HD, or High Definition, is the Holy Grail of home entertainment. We all want it, although most of us couldn’t define it beyond “It makes the picture look really sharp.” And so we’re ill-prepared for the onslaught of terminology, claims and battling standards that await us in those neon blue temples of technology.

When regulators mandated that Digital Television (within which HD is defined) become the broadcast standard by January 1, 2006 (this date was later moved out to February 17, 2009 because broadcasters couldn’t make the initial deadline), they did little beyond establish how the standard would work over the airwaves. That left it up to the marketplace to define the technology and services that will deliver HD over cable, on satellite and disc. And that, of course, lead to plethora of services all promising to deliver eye-searing video to your living room – and a plethora of standards to go along with them.

Is HD ready for prime time? Mostly. HD itself is clearly defined: Any video signal with resolution of 720 vertical pixels or higher in a 16×9 aspect ratio is considered HD. (Although HD sources are generally digital, they don’t have to be. See “HD Sources” below.) How you get that signal into your television, much less how you might record that signal – well, that’s a bit more complicated.

To help you sort through all the options, The Geek Beat presents our first “Geek 101″ technology guide – a three-part series on “Everything HD.” This guide is meant as an introduction to HDTV. If you already know the difference between 1080i and 1080p, know your Blu-ray from your HD DVD and why everything on an HD channel isn’t necessarily in HD, then this guide is not for you. But if you’re new to the HDTV world, or just want to brush up your Geek cred, read on.