Compact disk
A compact disk is the long form of a CD. It's that circular thing with a silvery backside that contains all the music/movies/data/shit/porn that you downloaded from the net is usually stored. It is what you call the principle portable data storage method for the late twentieth century. A CD comes in two sizes, the larger CD has a capacity of 700 MB, or 80 minutes of sound, and the smaller ones have a capacity of 185 MB, or 21 minutes of sound. There are three kinds of CDs. PRe-recorded CDs that comes with software / music / data already burnt in. CD-Rs where you get to burn data, and CD-RW where you get to burn as well aas erase data. As of now, portable data storage is changing over to flash drives and DVDs.