The kind of storage media being used has also undergone a sea change. The technology used to store and read data from the media has changed from magnetic to optical form. In the computer world "optical" refers to lasers, which can "see" and read data on optical discs. In optical drives data is stored in the form of small pits. These millions of pits are read by lasers as one and two and then converted to information for the computers. Data is stored in concentric circles on the media.



There are two basic forms of optical storage used in computers today: compact disc (CD) and digital versatile disc (DVD). These include optical media for CDs (CD-R, CD-RW) and for DVDs (DVD-R, DVD-RW, DVD-RAM). Compact disk storage space averages around 650 to 700 MB of data per disk. They can contain audio, data or both on the same disc. Most software for computers is distributed on CD formats.

DVD was the development for compact digital video format that also spun off into the data storage arena. DVD is seen primarily for video and has only recently really started to be used for software distribution. It however has more storage capacity than the CDs.

The use of optical drives for storing information has become popular and a number of products are available in the market. There are many advantages of using optical media like CDs and DVDs:

1.High Storage Density: Their storage density that is size versus capacity is much more than the tape drives that were available till now. They are compact in size and can store data upto 600-700 MB in CD and from 25 GB to 250 GB in DVDs.

2.Inexpensive and Convenient: They are very inexpensive and easily available. The size of these disks and the amount of data that can be stored in individual disks accompanied by fast speeds make them very convenient as data storage and data transfer devices.

3.Direct Access of Data: The data on these disks is stored in concentric circles and is read by focusing a laser on them. This allows for a random access to specific data. One does not have to go through the whole data to retrieve specific information as is the case with tape drives.

4.Safe from Magnetic Fields: The fact that data is stored on these disks optically and not magnetically ensures that the data stored is not harmed if placed in magnetic fields like an X-Ray machine.

There is basically one disadvantage of using optical drives and that is the discs getting physically damaged:

Delicate and Sensitive: These disks do not come encapsulated in any sort of permanent covering. In fact the surface on which the data is stored is completely exposed. This makes them very susceptible to getting damaged, physically or otherwise. Any human negligence or mechanic fault in handling them can lead to permanent data loss.

The disks are very sensitive to even the tiniest speck of dust, change of temperature or exposure to moisture and humidity. One has to be very careful while handling these and under no circumstances should the surface on which the data is stored should be touched. Even a dirty or faulty RW drive can damage the dIsk. It is prone to scratching, distortion, and breaking and needs to be handled carefully.

The main reason for data loss in the optical drives is also any damage suffered by the optical drive. The damage can be incurred due to two factors- human and mechanical. Yet, statistics prove that it is the human negligence which is responsible for the data getting lost more than the mechanical failure. They affect the life span of disks negatively.

CDs and DVDs are very sensitive to wrong physical contact, spills, scratches and exposure to unsuitable natural conditions. They should be held from the hole in their centre. Holding from the sides can firstly spoil the surface on which the data is stored or they can fall down and break. All sort of labeling especially on the side of data storage should also be avoided.

Storing optical drives also calls for a dust free, dry and moderate temperature environment. Proper storage and careful handling can ensure that we utilize the advantages of optical drive to the maximum while avoiding their shortcomings.