Disc

Optical data storage device that is round, flat, and ridged that is written to using a laser. An examples of a disc is a Blu-ray, CD, and a DVD.

Note: When talking about a disk or diskette, you're referring to a floppy diskette. However, when talking about a CD or DVD you should use disc, for example my movie is on that DVD disc.

Also see: CD definitions, Disk