The Compact Disc was the first popular optical storage media. The result of a collaboration between Philips and Sony, its original use was for playback of audio recordings. CDs are available in the following types based on the content they carry: CD A (Audio CD), Video CD (for video), Mixed Mode CD (Containing audio and other data types), Data CD (containing all forms of files), CD—I (CDs containing interactive content), and more. Based on their recording capability, we have CD-ROM (Read-only; all pre-manufactured CDs are of this type); CD-R (recordable once); and CD-RW (read and write many times). The original CD drive could read data at 150 Kilobytes per second, and every subsequent CD drive speed has been rated as a multiple of this speed. The laser used in a CD drive has a wavelength of 780 nanometres. The rated storage capacity is 700 MB.