How storage devices works


Optical Drives as Storage Devices

Storage is the key factor driving thefor a random access to specific data. One
advancement in the IT industry today. Thedoes not have to go through the whole data to
speed levels have increased, sizes haveretrieve specific information as is the case
reduced and prices have been stabilized.with  tape  drives.
Efforts are on to make data storage cheaper,
easier, faster and compact along with huge4. Safe from Magnetic Fields: The fact that
storage  capacities.data is stored on these disks optically and
not magnetically ensures that the data stored
The kind of storage media being used has alsois not harmed if placed in magnetic fields
undergone a sea change. The technology usedlike  an  X-Ray  machine.
to store and read data from the media has
changed from magnetic to optical form. In theThere is basically one disadvantage of using
computer world "optical" refers to lasers,optical drives and that is the discs getting
which can "see" and read data on opticalphysically  damaged:
discs. In optical drives data is stored in
the form of small pits. These millions ofDelicate and Sensitive: These disks do not
pits are read by lasers as one and two andcome encapsulated in any sort of permanent
then converted to information for thecovering. In fact the surface on which the
computers. Data is stored in concentricdata is stored is completely exposed. This
circles  on  the  media.makes them very susceptible to getting
damaged, physically or otherwise. Any human
There are two basic forms of optical storagenegligence or mechanic fault in handling them
used in computers today: compact disc (CD)can  lead  to  permanent  data  loss.
and digital versatile disc (DVD). These
include optical media for CDs (CD-R, CD-RW)The disks are very sensitive to even the
and for DVDs (DVD-R, DVD-RW, DVD-RAM).tiniest speck of dust, change of temperature
Compact disk storage space averages aroundor exposure to moisture and humidity. One has
650 to 700 MB of data per disk. They canto be very careful while handling these and
contain audio, data or both on the same disc.under no circumstances should the surface on
Most software for computers is distributed onwhich the data is stored should be touched.
CD  formats.Even a dirty or faulty RW drive can damage
the dIsk. It is prone to scratching,
DVD was the development for compact digitaldistortion, and breaking and needs to be
video format that also spun off into the datahandled  carefully.
storage arena. DVD is seen primarily for
video and has only recently really started toThe main reason for data loss in the optical
be used for software distribution. It howeverdrives is also any damage suffered by the
has  more  storage  capacity  than  the  CDs.optical drive. The damage can be incurred due
to two factors- human and mechanical. Yet,
The use of optical drives for storingstatistics prove that it is the human
information has become popular and a numbernegligence which is responsible for the data
of products are available in the market.getting lost more than the mechanical
There are many advantages of using opticalfailure. They affect the life span of disks
media  like  CDs  and  DVDs:negatively.
1. High Storage Density: Their storageCDs and DVDs are very sensitive to wrong
density that is size versus capacity is muchphysical contact, spills, scratches and
more than the tape drives that were availableexposure to unsuitable natural conditions.
till now. They are compact in size and canThey should be held from the hole in their
store data upto 600-700 MB in CD and from 25centre. Holding from the sides can firstly
GB  to  250  GB  in  DVDs.spoil the surface on which the data is stored
or they can fall down and break. All sort of
2. Inexpensive and Convenient: They are verylabeling especially on the side of data
inexpensive and easily available. The size ofstorage  should  also  be  avoided.
these disks and the amount of data that can
be stored in individual disks accompanied byStoring optical drives also calls for a dust
fast speeds make them very convenient as datafree, dry and moderate temperature
storage  and  data  transfer  devices.environment. Proper storage and careful
handling can ensure that we utilize the
3. Direct Access of Data: The data on theseadvantages of optical drive to the maximum
disks is stored in concentric circles and iswhile avoiding their shortcomings.
read by focusing a laser on them. This allows



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