The compact disc (CD) is a digital optical disc data storage format which can store and play digital audio recordings. Standard CDs have a diameter of 120 millimetres (4.7 in)…

The compact disc (CD) is a digital optical disc data storage format which can store and play digital audio recordings. Standard CDs have a diameter of 120 millimetres (4.7 in) and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MB of data.