Computers: Jargon buster

CD-rom: These operate in much the same way as an audio CD player, but can read information specially encoded for computers at high speed and in high volumes. Each disc can store more than 450 times as much information as one ordinary floppy disk - enough to store the Encyclopaedia Britannica twice over - including short clips of moving images, which gives a new dimension to both games and reference works.

Up to now CD-Rom drives have usually had to be added to systems, but more systems are being sold with a CD-rom drive as an integral part.

The cheapest way into CD-rom is Amiga's CDTV, in the shops at under pounds 300, and Philips CD-i, at under pounds 500, which offer interactive information packs and games using an ordinary television set as a monitor. At the high end, recordable CD systems are on their way.