An optical disk is a permanent storage device. A laser beam used to read and write data on an optical disk. It can store data up to 1 GB. For more explanation about the optical disk, types of optical disk, their advantages, and examples, let’s read the complete article.
Optical disk uses laser technology to read and write data. The LASER stands for Light Amplification Through Stimulated Emission Of Radiation. Laser beam writes on the surface by creating small pits (hole) in the disk.
Optical drive reads data by focusing a laser beam on the surface of the disk. A laser detects the presence of a pit. The presence of pit indicates 1 and absence of pit indicates 0. Laser beam converts these pits into digital data.
The amount of space required to record an optical bit is much less than a magnetic bit. Optical disk storage capacity is from 600 MB to over 1 GB. The optical storage is much faster than magnetic media.
Types of Optical Disk
Following are the major types of optical disks:
- WORM Disks
- Rewritable Optical Disks
CD-ROM stands for compact disk read-only memory. The data stored on CD-ROM can only be read. It cannot be deleted or changed. CD-ROM is a portable storage device. The data can be transferred easily by using CD-ROM. It can store about 650MB of data.
Uses of CD-ROM
- CD-ROM is mostly used to store a large amount of information like sound, color, graphics, and videos.
- It is often used to distribute new application software and games.
Advantages of CD-ROM
- It is the least expensive way to store large amounts of data and information.
- CD-ROM disks are durable and easy to handle.
- Information can be stored on CD-ROM for many years.
Disadvantages of CD-ROM
- The data cannot be edited.
- It retrieves data and information more slowly than magnetic disks.
Digital Video Disk (DVD)
DVD stands for digital video disk. It is similar to CD-ROM. It uses a laser beam with a short wavelength. The short wavelength reads smaller holes on the disk.
Data storage capacity of the disk is increased it the hole size is small. So the storage capacity of DVD ROM is much greater than CD-ROM. It can store up to 17 GB of data.
WORM stands for write once read many. It can only be read and cannot be updated or changed. It can store greater volumes of information than CD-ROM. Its capacity is 200 GB.
Rewritable Optical Disks
It uses several technologies to combine optical and magnetic disk technology to enable read and write storage. A 5 ½ inch rewritable disk can store up to 5 GB. These are normally used for applications using large volumes of storage with little update activity.
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