The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in October 1982 and branded as Digital Audio Compact Disc. The format was later adapted for storage of data .
The cd command, also known as chdir (change directory), is a command-line shell command used to change the current working directory in various operating systems.