A CD-R (Compact Disc-Recordable) is a thin (1.2 mm) disc made of polycarbonate with a 120 mm or 80 mm diameter that is mainly used to store music or data. However, unlike conventional CD media, a CD-R has a core of dye instead of metal.
A standard CD-R has a storage capacity of 74 minutes of audio or 650MB of data (though MB is printed on CDs as the binary prefixes haven't caught on in the industry, MB will be used in this article). Non-standard CD-Rs are available with capacities of 80 minutes/703MB

CD-R 74 Min $0.30 Each 74 Min Printable $0.35 Each 80 Min $0.40 Each