CD-Rom and DVD Drive Definitions

CD-ROM: Compact Disk - Read Only Memory. Maximum capacity: 650MB. These are the most common type of CDs.  Almost all software you purchase on CDs is in this format.

CD-R: Compact Disk - Writeable (i.e. write-once, read many times). Maximum capacity: 650MB.  Some older CD drives cannot not read these disks.

CD-RW: Compact Disk - Rewriteable. Maximum capacity: 650MB. Older CD drives cannot read these disks even with UDF reader software.

DVD: Digital Video Disk (also known as Digital Versatile Disk). Commonly used to store video information.

MPEG-2: A standard for compressing motion picture (video) files.

DVD Decoder Card: a plug-in circuit card (usually PCI) that is used in conjunction with a DVD drive to playback encoded video information (such as movies) from a DVD disk.

DVD Decoder Software: software is available (on cd-rom) that will allow you to use a DVD drive without a DVD decoder card.  However, the video from DVD movies and such may appear choppy on the screen because your CPU is having to do the processing that would otherwise be done by a decoder card.

UDF Reader: Universal Disk Format reader. Software that allows "multi-read" cd-rom drives to read cd-rw disks that were created in UDF format.