Microsoft Office Tutorials and References
In Depth Information
ESSENTIAL INTRODUCTION TO COMPUTERS
An optical disc is a portable storage medium that consists of a flat, round, portable disc made
of metal, plastic, and lacquer that is written and read by a laser. Optical discs used in personal
computers are 4.75 inches in diameter and less than 1/20 of an inch thick. Nearly every personal
computer today has some type of optical disc drive installed in a drive bay. On these drives, you
push a button to slide the tray out, insert the disc, and then push the same button to close the
tray (Figure 19).
Many different formats of optical discs exist today. These include CD-ROM, CD-R, CD-RW,
DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, and DVD+RAM. Figure 21 on the next page
identifies each of these optical disc formats and specifies whether a user can read from the disc,
write on the disc, and/or erase the disc.
A CD-ROM (compact disc read-only memory) is a type of optical disc that users can read but
not write on (record) or erase — hence, the name read-only. A typical CD-ROM holds from 650
MB to 1 GB of data, instructions, and information. Software manufacturers often distribute their
programs using CD-ROMs.
To read a CD-ROM, insert the disc in a CD-ROM drive or a CD-ROM player. Because audio
CDs and CD-ROMs use the same laser technology, you may be able to use a CD-ROM drive to
listen to an audio CD while working on the computer. Some music companies, however,
configure their CDs so the music will not play on a computer. They do this to protect themselves from
customers illegally copying and sharing the music.
For more information,
weblink and then click
FIGURE 19 On optical disc drives, you
push a button to slide out a tray, insert the
disc, and then push the same button to
close the tray.
Push the button to
slide out the tray.
Insert the disc,
label side up.
Push the same button
to close the tray.