What are the advantages of a compact disc?

CD-ROM is compact-disc read only memory.

it generally holds aboout 650mb of data or 74 minutes of audio.

it's generally less expensive than DVD and blue-ray, although generally DVD and blue ray devices can read CD-ROM data as well.

CD-ROM is a format (AUDIO CD, DATA CD), storage media (CD-ROM Disc), and type of device (CD-ROM Drive).