Understanding Computer Terms
CD-RW drive
A drive with three laser powers that can write to a CD-RW, erase the data, or read the data. A high-power laser melts the crystalline recording layer. It cools quickly, sets without forming crystals, and absorbs the laser beam. Data is written in pits that form as the non-crystalline material shrinks. A medium-power laser erases the data. It melts the recording layer at a lower temperature for a longer period of time. As the phase-change material cools, crystals form that reflect the laser beam. The high-power laser can then overwrite the crystalline material. A low-power laser, which does not alter the state of the recording layer, reads the data. A CD-RW drive can read CD-ROMs, CD-Rs, and CD-RWs. It can write to both CD-Rs and CD-RWs.
CD Text
An audio CD format in which up to 5000 characters of CD information (title, artist, and song titles) are written into the Table of Contents of a CD. The information is displayed when the CD is played back on CD Text-enabled players.
chat
An Internet feature that allows you to exchange typed messages with another person (or group of people) in real time. A message you type is instantly displayed on the other person’s computer.
click (left-click)
To press and quickly release the left mouse button to select an item.
close disc
To “close” a recordable disc so that no further data can be written to it. This is done when the last session’s lead-in is written. The next writable address on the CD is not recorded in the lead-in, so that the CD-Recorder in subsequent attempts to write has no way of knowing where to begin writing. Note: It is not necessary to close a CD to read it in a normal CD-ROM drive.
Learning More About Your Computer | 5–7 |