It is being hailed as nothing short of a revolution - the most important event in television history since the first fuzzy waves hit the nation's sets from Alexandra Palace 62 years ago. Digital television is being launched in November with fanfares, hype, excitement - and, well, no little confusion.

So, what exactly will it mean for the average television watcher? More choice? Better quality programmes? Or merely another expensive way of tuning into third-rate American soap operas?

Despite broadcasting watchdog the Independent Television Commission throwing open the bidding for digital licences two years ago, a recent survey found that more than a quarter of the population hadn't even heard of Digital TV and more than 60 per cent were confused about what it would offer. The question is, why DO you need digital TV? Here's a low-down of those niggling questions, and the answers.

What is digital television?

The key difference with digital broadcasting is the width of the signal.

The breakthrough came when it was discovered that digital signals were much thinner than analogue ones.

Such compression allows more information to be squeezed into the same spectrum.

This means one of two things for broadcasters - they could stick with the same number of stations but broadcast them with much clearer pictures and sounds, or leave the quality virtually unchanged and can cram in many more stations. Britain, in common with Europe, has opted for the latter. Will picture quality improve?

There will be an improvement due to the nature of digital. Because the picture will be made up of binary digits - or ones and zeroes, like the waves from mobile phones or the information in CDs - it can be duplicated perfectly from source, unlike analogue, so will not be affected by weather or interference.

Editor of Home Entertainment magazine, Rob Lane, believes it will be better. "Digital TV is happening now," he says, "yet most of us are totally unaware of the sharper pictures, clearer sound and greater choice it offers. It's set to open up the world of TV in much the same way that the microchip heralded a new era in computing and sound revolutionised cinema."

Why are they changing now?

Cynics would say it's because it's cheap.

The kinder view is that it offers the consumer the chance to receive CD-quality television and be part of a change in the nature of broadcasting forever. Cheaper cameras, the lower operation costs, the versatility of being able to transfer material onto a variety of outlets from normal printers to computers and the reduced transmission costs, are probably nudging the 'revolution' on quickly.

There are three main companies who currently have licences - BSkyB, the BBC (transmitted through the Carlton and Granada consortium ONdigital) and a Digital Cable service.

What will it cost?

There are two digital options - digital terrestrial and digital satellite. The first is a basic package of 12 channels, and the second is a far more extensive service.

For most people's needs, digital terrestrial is the better option.

The theory is, all you need to do is buy a digital set-top box for about £200, which will work also for digital satellite, and pay £10 a month for the terrestrial service, the figure ONdigital is proposing. You could also invest in a new up-to-the-minute digital TV set, about £200-£300 more than an analogue one, expected to go on sale this Christmas.

But in practice...?

There are a few problems. The essential stumbling block is that up to 3.5 million rooftop aerials which should, in theory, be able to pick up the transmissions, are too old, of the wrong type, or pointing in the wrong direction. Also, if companies produce their own set-top boxes consumers may have to buy more than one to get all the channels. It is more complicated for digital satellite viewers - the 3.6 million Sky subscribers who have an analogue dish will not be able to use it for digital - it could cost either BSkyB or its customers between £400m and £600m to install new equipment.

And the programmes?

ONdigital will include BBC News24, BBC Choice (a classic repeats channel) and ITV2, a new ITV channel. Digital BSkyB will offer Sky Soap, Sky Sports News and ten music channels called Sky Music choice. The other service, Digital Cable TV, will be launched in the Spring.

So the end of pay-per-view?

No. BSkyB may still be charging premium rates for special sports matches.

Is it the end of analogue TV?

Not necessarily. A recent Government Green Paper outlined the difficulty in predicting the development of digital, so an 'overlap' between digital and analogue was preferable to an either/or approach.

But David Docherty, the deputy director of television in BBC Broadcast, is confident of digital taking off in a big way. He said: "I think genuinely it will be one of those things like colour TV.

"You see it at your neighbour's house and you say 'I'd like one of those'."

What about digital radio?

If you have a spare £1,000, you could also splash out on a digital radio.

The technology converts radio broadcast signals into binary digits in the same way as television. It will offer more choice - eventually more than doubling the 230 UK radio stations now available.

People listen to the radio for an average of three hours a day (including car radio) - about the same amount as television.

But the reason a new radio is so expensive is that it is not being subsidised by broadcasters or manufacturers - leading some to doubt its long-term viability .

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.