QUESTION: I'm glad I'm able to ask this question anonymously since I often feel that everyone else knows more about computers than I do. Our computer at home came equipped with a CD player but now we feel confident enough to start making our own CD recordings especially for backups. When we went to the computer store in town we saw available on the shelf several different types of CD players for computers. They also had different stacks of confusingly labelled blank CDs. We have no idea what the difference between them all is supposed to be. In the particular store we were in there was nobody available to explain the differences between them and we wondered if you could tell us what to look for and what is available?

ANSWER: That's an excellent question. The trick for me is in finding out what people want to know about. Sometimes the questions are not obvious.

You should view the whole CD-ROM player subject as a matter of the evolution of a basic and important device, the optical drive, eventually splitting into two somewhat distinct categories. CD-ROM stands for compact disc read-only memory, this means that this first and simplest type of CD-ROM player, which is included in virtually every computer will play back a CD, either a data CD or a music CD, but will not be able to write to a recordable one.

For a long time these players got faster and faster. This didn't make any difference to the playing back of music CDs, but it did mean that the contents of data CDs could be transferred from the CD into the computer for processing at a much faster rate. Eventually came the big step - CD recorders became available. These machines, except for the writing on the plates on the front look identical to the CD-ROM (play only) units. Now, for the first time you could pop in a blank CD and make your own data or music CD recordings using software designed for that purpose, a basic version of which is included with Windows XP. This is called 'burning' a CD.

Meanwhile, developing on the other evolutionary branch of optical drives were the DVD players. Originally DVDs were intended for playing back factory-manufactured movies on your computer. These were separate distinct devices which you could order with your computer or purchase and install later. Most computers so equipped had two optical disk drives. Both drives could playback CDs but only the CD recorder could record new CDs. Nowadays it is quite common to find a drive that can play and record CDs as well as be able to play back, but not record, DVDs, a sort of combination unit.

The next big step is a player that records DVDs too. This all-in-one unit will also play all types of CDs, both data and music, make recordings on blank CDs and play all types of DVDs, both movies, music and data, and also, given the correct software, copy DVD movies and record to blank DVDs.

Okay, that was the complicated part, but in case you've pondered the boxes or spindles of blank CDs in DVDs on the shelves of stores and been overwhelmed by the seemingly similar descriptions on the packages Here follows a description of what all those acronyms mean and an explanation of the different types all recordable media, that is blank DVDs and blank CDs.

CD-Rs are blank compact discs that are recordable and can contain approximately 700MB of data or music, either as MP3 compressed music files or conventional CD music format. They can even hold a type of compressed video footage said to be equal in quality to the VHS tape. CD-RWs are essentially the same thing as CD-Rs except that the blank media can be erased by the computer and written to all over again, over and over, perhaps hundreds of times. However, not every CD player that can read a CD can read a CD-RW.

DVDs follow very much along the same lines with the DVD ROM blank now disk available and also a DVD-RW reusable blank disk also too. However, just when you figured you had all that clear in your head I have to tell you that there is a competing format war, actually more like a scuffle, faintly reminiscent of the old Beta versus VHS format wars of the early 1980s.

Currently there are two competing types of blank DVD, they are DVD-R versus DVD+R. If you're smart and careful when you buy a DVD recorder for your computer you'll make sure that the one you select can handle both types. That way it doesn't matter who wins the war. The great thing about recording on DVDs is the vast data storage capacity available compared to blank CDs. At the present time blank DVDs can record about 4,700MB (4.7GBs) of data as opposed to 700MB on a blank CD. If you're backing up something important and fairly voluminous like your new digital photos or your burgeoning e-mail collection and you find that you're obliged to keep track of a handful of newly recorded CDs you will suddenly appreciate the possibility of fitting everything on a single blank DVD.

In Japan (where else?) they have already demonstrated DVD recorders of the next-generation which will be able to record twice as much data utilising multiple recording levels on a recordable DVD.

I'm old enough to remember when a blank floppy disk with a capacity of 1.44MB was considered useful.

James W. Lapsley of ComputerWorks, specialises in PC repairs, upgrades and advice for the home and small office user. ComputerWorks welcomes your questions and comments. Send your PC questions by e-mail to computerworks@logic.bm or by phone to 293-0992.