Compact Discs (CDs) are optical storage media that use a reflective layer to store digital data in the form of tiny pits and lands. They have a shiny, round appearance with a diameter of 12 centimeters (4.7 inches) and a hole in the center. CDs revolutionized the music industry in the 1980s, providing a more durable and convenient alternative to vinyl records and cassette tapes. They can hold up to 700 megabytes of data and are commonly used for storing audio recordings, software, and other digital content. The iconic 💿 symbol represents the concept of Compact Discs and is often used to denote music or media-related topics.