Standing for "high definition" in this scenario, it means a better picture quality in either viewing or having images being digitally transmitted to a compatible screen. Most people associate HD with flat screen TVs, either LCD or plasmas, where there are several varieties and variations of standards and qualities.
The underlying benefit of which is just how good the image on the screen looks. From here there's a range of sources to deliver the best picture.
This comes along in one of two common ways, from a multiple-channel system or high definition media playback. The first is either Sky, Virgin Media or Freesat boxes with high definition capabilities, or Blu-ray and HD DVD discs and their associated players.What are the variations of the technology?
The standard way of viewing pictures on a cathode ray tube of yesteryear was only based on 625 lines of information on the screen. The basic high definition screen format is more or less double that with 1280 x 720 pixels, often referred to a 720. This is a dramatic leap from the old TVs and shouldn't be seen as only "double the quality" in anyway shape or form - it's way beyond that.
A step up from that is known as 1080, either seen as 1080i or 1080p. This is based on 1920 x 1080 pixels and is therefore a much higher viewable standard, with an image that benefits from a larger screen.
Within the 1080 standard, there's a p and an i variation. This means Progressive and Interlace and basically comes down to how the image on the screen is refreshed. The p option offers the best with the image being frequently fully refreshed whereas the other option, every other line is refreshed instead. This still looks good, but on pictures such as fast sports action or high-octane car chases in Bond films, Progressive looks far, far better.Why should I care?
The better the image quality, the better your enjoyment – it can be boiled down to just that. With the likes of the Playstation 3 having Blu-ray built-in and the Xbox 360 now sporting an HD connection, the picture benefits can already be seen without forking out for Sky or Virgin boxes.
Some that have been around long enough have summed up the experience of seeing an HD movie for the first time as similar to seeing a colour TV going from black and white.
Once you've seen a high definition movie on a decent HD screen you will not want to go back to anything else. It's as simple as that.What's a good example in practice?
Both Sky and Virgin now offer up boxes showing a high definition picture, as does the newly emerged Freesat – which is more or less Freeview from a satellite dish, with some HD channels. Most known makers of TVs offer up LCD high definition screens, with the plasma option costing more in most cases.
We've already mentioned the Playstation 3 with Blu-ray and the Xbox 360, which needs an extra drive to play HD movies and is currently only for HD DVD movies - the now-defunct rival to Blu-ray. There are also stand-alone Blu-ray disc players, much like normal DVD players, but geared for playback of its own media type.
There's also a more advanced option of upscaling DVD players or similar devices. This is where the signal is boosted electronically to obtain a near HD quality. It just extends the life of your existing DVD collection, before you fully make the switch over to Blu-ray discs.Is there a competing technology that I should be aware of?
There really isn't another technology around to compete with HD screens or its quality. The only thing to mention here is that not all channels on both Sky or Virgin Media are in an HD format. In saying that, it's still better to see any images on an HD screen than not at all.
There will be more channels within time. When the UK catches up with the USA where nearly all their basic channels are in high definition and the programs are made in this way too – that will be a good day.
In pre-empting this move, it's always wise to hedge your bets and go down the HD route. The only deciding factor is to either go for a likely cheaper 720 screen or a 1080 screen at this time.What is in store for the future?
The future holds more and more channels being transmitted digitally, and more and more in HD too. With the analogue to digital switch over being just around the corner, the clock is ticking away fast.
At the end of the day, an HD TV is only as good as the content delivered to it. You'll be disappointed by watching videos from the late 80s on a vast 50-inch screen, although you'll be astounded and blown away by watching "Quantum of Solace" on that very same TV.
The high-def capable consoles have games written solely for high definition screens and has online content aimed for HD users too. Whether you like it or not, high definition is here to stay for the foreseeable future.
The future is bright and it's all in HD.