DVD-Roms not only play DVD media, including DVD movies and burned DVD's, they play CD media as well. DVD media holds so much more data (4.7 gigabytes for DVD's compared to about 700 megabytes for CD's, that's about 6.5 TIMES the storage) they're quickly becoming the replacement for CD-Rom drives, the same way CD-Roms replaced floppy drives for most applications.

There are a few factors to know about when buying a DVD-Rom. Most DVD-Roms are either 12x or 16x speed, which is how fast it can access the disk. If you're wondering what the x stands for, it stands for multiplication, so 16x means sixteen times the standard read rate, which the standard read rate is 1352 KB (kilobytes) per second. Multiply 16 times 1352, and you get 21632 KB per second, which really means it can read 21.6 megabytes per second. The higher the number, the faster it can read.

The other factor to consider is what format of DVD's it will play. Some DVD-Roms have restrictions on what kind of formats it will play. Most will play about any kind of format on the market right now, but it is something to look for, especially if you burn your own DVD's.

Here's my favorite computer site with tons of DVD-Roms to choose from