Both technologies use a blue laser to write information. It has a shorter wavelength so more data can be stored.

A Blu-ray disc will eventually be able to store 50GB of high-quality data, while Toshiba's HD DVD will hold 30GB. A standard DVD holds just under 5GB.

The disc formats offer much better quality audio and video, while next-generation console games will have stunning graphics and will fit onto a single disc.

Format wars

The two rival systems have been battling to win support for their competing approaches from technology companies and Hollywood studios.

Toshiba, with NEC, Sanyo and others, is pushing HD DVD; while backers of Sony's Blu-ray discs include Samsung, Dell and Apple.

The HD DVD format was given a huge boost last year when technology giants Microsoft and Intel threw their considerable weight behind the standard.

Hollywood is also still split over the new formats. Companies like Disney and 20th Century Fox have sided with Sony, while the supporters of HD DVD include Universal.

Warner Bros and Viacom have said they will support both.

However, the format war, which has been likened to the Betamax-VHS fight in the 1980s, may ultimately be won in the games console market.

Gaming is a $20bn industry worldwide, so is as important as the film industry in terms of money to be made.

Games consoles also tend to drive early adoption of technology because hardcore gamers, keen to get their hands on the latest titles, are prepared to buy the latest technology.

It is estimated that Microsoft sold 20 million of its original Xbox console, while Sony has sold four times that amount of its Playstation 2. Both consoles brought DVD players into people's living rooms.

Sony's Playstation 3, which will be launched in November, will come with a Blu-ray drive as standard.

Owners of the Xbox 360, which is already available around the world, will have to buy a separate HD DVD drive when they become available.

Games giants, such as Electronic Arts and Vivendi, have both backed the Blu-ray format.