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.

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