The compact disk, commonly known as CD, is an optical disk used to store digital data. It was originally invented to only hold audio but later on it can store video, software, text, and graphics. The compact disk contains transparent coating, which allows information to be received from a laser beam. Not only can a compact disk provide information but it can take in information as well. Compact disk is able to store large amounts of data by compressing it together.
Compact disk comes in different sizes and formats.
One such format is the compact disk read only memory commonly known as CD ROMs. It is about twelve centimeters in diameter. CD ROMs have data that can be accessed yet data cannot be erased on a CD ROM and additional data cannot be added. Many things can be stored on a CD ROM like audio or video. It can contain as much as 900 megabytes of information that is an equivalent to 99 minutes of audio or video.
Next is Digital Video Disk or DVD for short. DVDs can contain 4.7 gigabytes on a single layer on one side of the optical disk. It has many uses like for storing video. It can play videos when inserted to a DVD player. There are also DVDs that can record video on its disk known as DVD-R. It can record video only once. After recording a video the first time data cannot be erased or changed. With DVD-RW it can be record videos and be rewritten.
Then there is the Universal Media Disk or the UMD. It is about 6 centimeters in diameter. It is different from other optical disk in that it has a protective shutter. Its data can contain movies, music, games, and even TV shows. Its design is to be played on a PlayStation Portable, which is a handheld video game system. It is a read only disk in which it data cannot be erased or rewritten. It can store 900 megabytes on a single layer or 1.8 gigabytes on dual layers. It uses a MPEG4 AVC codec to play videos.
Finally there is Blu-ray. It is an optical disk that can hold more information then the standard DVD. The disk is the same size as standard DVDs and CD-ROMs. Blu-ray uses a shorter wavelength, which explains why it is able to hold more information then a standard DVD. It is able to play high-definition video. Blu-ray gets its name from using a blue-violent laser then a red laser commonly used on DVDs. As time went by there has been success in adding more memory in Blu-ray thus allowing more information to be stored on the optical disk.
The benefits of owing a compact disk is that it takes up less space then the video home system tapes. Compact disk offers better quality as oppose to other media such as videotapes. Unlike videotapes where the quality gets lower every time the videotape is played CD’s quality remains the same regardless how many times it has been played. CDs are also cheaper to produce then ROM cartridges. Even though CD ROMs have a longer load time compared to ROM cartridges it can still hold more data. CDs are easy to use as well. All you have to do is put it in an appropriate media player and the media will usually automatically play depending on what kind of format it is.