CD (Compact Disc) is a digital optical disc data storage format that was co-developed by Phillips and Sony in 1982. CDs are an affordable and reliable way to store data and have a capacity of up to 700 MB. CDs can be used to store music, video, images and other data.
CDs are made of a 1.2mm thick polycarbonate plastic core, which is coated with an aluminum reflective layer. A thin layer of protective lacquer is added to the top of the CD. Finally, the data is printed on the top of the lacquer in small bumps that make up the pits and lands of a CD.
The optical pickup in the CD player reads these pits and lands, which represents the digital data. Once the data is read, it is sent to an output device such as a speaker, headphone, or computer.
CDs have been the most popular digital media format for music since its introduction in the 1980s. CDs are preferred over cassettes and vinyl records because they are smaller, more durable, and easier to transport. CDs also have better sound quality, with the ability to store more data than other physical media formats.
CDs have also been widely used to store computer data, such as software programs and digital files. CDs are more durable than other digital media formats, such as floppy disks and flash drives.
The popularity of CDs has been in decline since the introduction of digital media players and internet streaming services. These streaming services allow users to store music and other digital media files online and have access to it from any computer or device connected to the internet. Despite this decline, CDs are still widely used to store music and computer data.
