check box

A small box in a dialog box or property page that can be selected or cleared. Check boxes represent an option that you can turn on or off. When a check box is selected, an X or a check mark appears in the box.

clear check box

To turn off an option by removing the X or check mark from a check box. To clear a check box, you can click it, or you can select it and then press the Space key.


To press and release a mouse button quickly.


A temporary storage area in memory, used to transfer information. You can cut or copy information onto the clipboard and then paste it into another document or application.

Close button

Remove a window or dialog box, or quit an application. To close a window, you can click Close on the window menu, or you can click the close button icon in the upper right corner of the dialog box. When you close an application window, you quit the application.


A cluster is the unit of disk space allocation for files and directories. The filesystem does not allocate individual disk sectors, but contiguous groups of sectors, called clusters.

code page

A page that maps character codes to individual characters. Different code pages include different special characters, typically customized for a language or a group of languages. The system uses code pages to translate keyboard input into character values for non-Unicode based applications, and to translate character values into characters for non-Unicode based output displays.

command shell

The command interpreter that is used to pass commands to the operating system.

computer name

A unique name of up to 15 uppercase characters that identifies a computer to the network. The name cannot be the same as any other computer or domain name in the network.


A software link between a client and a shared resource such as a printer or a shared directory on a server. Connections require a network adapter or modem.


See cyclic redundancy check.

current directory

The directory that is currently displayed in a panel.


An onscreen indicator, such as a blinking underline or rectangle, that marks the place at which a keystroke will appear when typed. In applications and operating systems that use a mouse, the arrow or other onscreen icon that moves with movements of the mouse.

cyclic redundancy check (CRC)

A procedure used on disk drives to ensure that the data written to a sector is read correctly later. This procedure is also used in checking for errors in data transmission.

The procedure is known as a redundancy check because each data transmission includes not only data but extra (redundant) error-checking values. The sending device generates a number based on the data to be transmitted and sends its result along with the data to the receiving device. The receiving device repeats the same calculation after transmission. If both devices obtain the same result, it is assumed that the transmission is error-free.