CD-ROM

Stands for "Compact Disc Read-Only Memory."

CD-ROM is a read-only optical media format that uses CDs to store data. A computer with an optical drive can read, but not write, data on a CD-ROM. A single disc can store up to 700 MB of data. Some CD-ROM discs, known as "Enhanced CDs," store a combination of audio tracks and a data track. CD-ROM discs were often used to distribute software and video games in the 1990s and 2000s before eventually being replaced by higher-capacity DVDs.

CD-ROM discs and audio CDs are physically identical, storing and retrieving data in the same method. Digital data is encoded and stored as a series of pits on a flat reflective layer on the bottom of the disc. The laser in the optical drive reads these pits, then decodes the data. The only difference between the two is how the data is formatted — multiple PCM audio tracks on an audio CD, or a single track containing data on a file system on a CD-ROM.

An optical drive can spin a CD-ROM disc at a significantly higher speed than an audio CD player. A CD spinning at the standard rate for audio playback supports a data transfer rate of approximately 150 KB/s; at this speed, reading an entire CD-ROM full of data takes almost 80 minutes. CD-ROM drives are classified by how many times faster they can spin, with many drives capable of 40x (6,144 KB/s) or more.

Updated October 25, 2022

Definitions by TechTerms.com

The definition of CD-ROM on this page is an original TechTerms.com definition. If you would like to reference this page or cite this definition, you can use the green citation links above.

The goal of TechTerms.com is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about the CD-ROM definition or would like to suggest a new technical term, please contact us.

Want to learn more tech terms? Subscribe to the daily or weekly newsletter and get featured terms and quizzes delivered to your inbox.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe or change your frequency setting at any time using the links available in each email.

Questions? Please contact us.