With Sky launching its Sky HD service in the UK today, Pocket-lint has put together a guide to what HDTV is all about, what kit you need to get it and what it is all about.

What is HDTV?

High-definition television or HDTV is a new standard of television broadcasting that provides a considerably sharper picture meaning the image on your television, providing you have a HD-Ready television, will be crisper and clearer.

So why would I want it?

Just like DVD over Video, the image quality is considerably sharper than what you are used to at the moment. Increased quality of signal means you should get a better viewing experience especially for movies, sport and nature documentaries.

Will I need new equipment to get it?

Yes. You will need to get either a Sky HD box from Sky or a TV Drive box from Telewest, which is similar to a Sky or Freeview set-top box.

What else will I need on the equipment front?

In addition to the decoder you will need to get yourself a HD-Ready television or projector. Prices start from around £600 for a 32-inch flatscreen model however if you are looking to immerse yourself into the experience we would recommend a 40 or 42-inch model. If you are really wanting to push the boat out, you'll need to get yourself a Dolby Digital 5.1 surround sound system.

What's the cost?

Sky's HD package will currently cost you £299 for the decoder and then an additional £10 a month for the HD service on top of your current Sky subscription, making it over £50 a month for all the channels. Telewest's pricing is a bit harder to understand as you can bundle in broadband and telephone services into the mix. However to add HD to your current package will cost you £10 to £15 a month. A similar package to Sky will cost £55.

What's the difference between the two services?

Not much. Telewest are offering a HD on demand service that allows you to access shows like Lost and Desperate Housewives, and more importantly for the World Cup all the ITV games. Sky however does currently have a bigger content offering with 11 dedicated channels showing HD content on a daily basis.

Can I get HDTV any other way?

Not at the moment. The BBC is running a trial with 450 homes in London with ITV however this is now closed to new participants. Unfortunately, Freeview box owners cannot get HDTV because there isn't enough room on the spectrum for high-definition signals.

If I get HDTV will everything be high definition?

No. Only programmes shot in HD will be shown in HD. The BBC has said that it plans to film everything in HD by 2012 and the majority of new American dramas are being shot in HD already such as 24, Lost and Desperate Housewives. However shows like Eastenders and Corrie won't be.

Okay, so what can I watch?

From launch, Sky HD will include the BBC, a Sky Sports channel, Sky One, Artsworld, a Sky Box Office channel and two Sky Movies channels as well as the Discovery Channel in HD. Telewest are offering BBC, ITV as well as on-demand television shows and movies.

I've heard there are a number of different formats, is that true?

Both Telewest and Sky HD support both the two HDTV formats 1080i and 720p. The difference between the two is how many lines, and therefore detail, is shown on the screen. Any TV you buy today or have bought in the last year that says it is HD ready will support both.

So why the two formats then?

The idea behind the two formats is to cope with different amounts of information. Although not official broadcasters are already saying that 720p will be used for fast moving action such as football games or where there is lots of detail happening quickly. 1080i is expected to be used for documentaries and films so the detail and colour is sharp and vibrant.

Brilliant, where do I sign?

To get Sky HD you need to sign up to the service online via the company's website. However rumours are surfacing that due to high demand and a delay in getting the boxes to the UK, new subscribers could have to wait until August. As for Telewest, you need to live in a Telewest area.

Is HDTV the same as HD-DVD or Blu-ray?

No. HD-DVD and Blu-ray are the next generation formats for DVD offering the same picture quality as HDTV. However you do not need a HD-DVD or Blu-ray player to watch HDTV. What you do need though, is a HD ready television.