A CD-ROM is a pre-pressed compact disc

Compact Disc

The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

 that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book”

Yellow Book (CD standard)

The Yellow Book is the standard that defines the format of CD-ROMs. The Yellow Book, created by Sony and Philips, was the first extension of the Red Book. It is named after one of a set of color-bound books that contain the technical specifications for all CD and CD-ROM formats.-External links:The...

 standard developed by Sony

Sony

, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

 and Philips

Philips

Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 adapted the format to hold any form of binary data

Binary file

A binary file is a computer file which may contain any type of data, encoded in binary form for computer storage and processing purposes; for example, computer document files containing formatted text...

.

CD-ROMs are popularly used to distribute computer software, including video games and multimedia applications, though any data can be stored (up to the capacity limit of a disc).