(abbrev) :
compact disk: A form of digital media that is based on the use of a laser to read from a plastic disc in a reader device known as a CD drive. It comes in several varieties including the
CD-ROM (ROM=read-only memory) which cannot be written to except during manufacturing, the
CD-R (recordable), which can be written to exactly once, and the
CD-RW (re-writable), which can be written to as many times as one wishes (to a limit);
Certificate of deposit: used by financial institutions