Page 57 - DCAP101_BASIC_COMPUTER_SKILLS

Basic Computer Skills

Notes 3. Optical disk drives do not have any mechanical read/write heads to rub against or
crash into the disk surface. This makes optical disks more reliable storage medium
than magnetic tapes or magnetic disks.

4. Optical disks have data storage life in excess of 30 years. This makes them better
storage medium for data archiving as compared to magnetic tapes or magnetic disks.

5. Since data once stored on CD-ROM/WROM disks becomes permanent, the danger of
stored data getting inadvertently erased/overwritten is not there.
6. Due to their compact size and lightweight, optical disks are easy to handle, store, and
port from one place to another.
7. Audio CDs can be played on a computer having a CD-ROM drive along with a sound
card and speakers. This allows computer systems to be also used as music systems,
whenever desired.
8. A computer having a DVD drive can be used to play DVDs allowing it to be used for
watching videos such as movies.

Limitations
1. CD-ROM and WORM disks are read-only (permanent) storage medium. Data once
recorded, cannot be erased. Hence, they cannot be reused.
2. Data access speed for optical disks is slower than magnetic disks.
3. Optical disks require more complicated drive mechanism than magnetic disks due to
the need to have laser generating source and detection lens that require precision
engineering and careful handling.

4. Since optical disk is a removable media, it is prone to scratches, dust, sticky prints
(including fingerprints), etc. while handling. Hence, they need careful handling.

5. When used for off-line storage, they should be labeled properly for easy identification.
4.1.2.3 Uses of Optical Disks
Optical disks are used for following purposes:

1. For distributing large amounts of data at low cost. For example, a complete encyclopedia,
dictionary, world atlas, dictionary of quotations, biographies of great people, information
about all educational institutions of a particular type in a country, etc. are often
distributed on CD-ROM disks.

2. For distribution of electronic version of conference proceedings, journals, magazines,
books, product catalogs, etc.

3. For distribution of audio such as songs.
4. For distribution of new or upgraded versions of software products by software vendors.
5. For storage and distribution of wide variety of multimedia applications such as video
games.
6. For archiving of data not used frequently but which may be used occasionally.
7. WORM disks are often used by end-user companies to make permanent storage of their
own proprietary information. For example, many banks use them for making a
permanent record of their daily transactions.
8. DVDs have become a popular medium for distribution of movies.

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