No doubt you have noticed, at the least from the title of this post, that there are a huge number of different types of optical media. You can use five broad classifications:

*Burnable or not burnable: CD (Compact Disk) and DVD (Digital Video/Versatile Disk), with no extension, means that it is not writable; it must be pressed with a special process in a factory.

*Write-once/Rewritable: a -R (Recordable) after CD or DVD means it cannot be erased. You can write to the disk multiple times (through a geeky process called "multiple sessions"), but you cannot erase anything on the disk. A -RW (Rewritable) means that it can be erased and rewritten on the same part of the disk, much like a gigantic floppy disk (and seemingly almost as slow).

*CD/DVD: A CD is the original optical media and can hold up to 700MB. A DVD can hold up to 8.5GB, but it is usually limited to 4.7GB.

*For DVD's, + or -: the - came first and is older, less reliable, slower, but more compatible technology. + is newer and you can write faster to it.

*For DVD's, DL or not DL: DL stands for Double Layer, and a DL DVD can hold up to 8.5GB, but is only readable or writable in special DL drives.

Most of these different criteria can be combined into nearly endless permutations, and there are even some more specialized types, such as "Double Sided" DVD's, which have writable surfaces on both sides of the disk; however, double-layer has made this technology nearly obsolete.

So which one should you buy? Well, it's a really complicated question, but I've tried to boil it down into some simple criteria. Before you buy anything, make sure your drive can use it; look on the front of the drive (eject it if the front is covered by a plate) and look at the symbols. If you want to burn Double Layer disks, you need a DVD DL drive. Look carefully for the DL. If you want to burn some type of disk that your drive can't burn, you can replace your drive; see http://www.thetechnicalgeekery.com/insi ... cdrom.html for details.

*If you're burning audio CD's, go with CD-R. It's the most compatible and should work great--but you'll have to get out another one and reburn if you want to change the disk.

*If you're doing a small amount of backup or moving data from computer to computer, you should probably go with CD-R. If you back up or move data a lot and don't need to keep the contents for long periods of time, go with CD-RW. It costs more at first and runs a bit slower, but it saves lots of money and CD's in the long run.

*If you're making movie DVD's, go with DVD+R. If you burn a DVD+R and it doesn't work where you try to play it back, go with DVD-R instead.

*If you're backing up large amounts of data frequently, go with DVD-RW's.

*If you need large amounts of space, go with DL DVD's; I don't recall seeing DL DVD-RW's anywhere, though.

*If you all else fails and you just can't figure out what to buy, look at how much space you need. If it's less than about one and a half gigabytes, go with simple, tried-and-true CD-R's. If it's more than that, go with DVD+R's. And if you go above about 10-15GB, you should start looking at other solutions, like external hard drives. (http://www.thetechnicalgeekery.com/insi ... exthd.html).

You may just need to try a few types until you find what's right for you. Here's hoping choices will be simplified in the future!