Compact disc
Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM). Several other formats were further derived from these, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Disc (VCD), Super Video Compact Disc (SVCD), Photo CD, PictureCD, CD-i, and Enhanced Music CD. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan.
Discman
The Discman was Sony's first portable CD player, the D-5 (North America and various other countries)/D-50, which was the first on the market in 1984, and adopted for Sony's entire portable compact disc player line. The name was changed to CD Walkman worldwide in 2000 along with a redesigned "Walkman".