Diskeeper 10 User's Manual

84 Glossary
central processing unit (CPU): The part of the computer hardware that controls the computer’s overall
operation and performs computations. Most modern CPUs are built into a single integrated circuit or chip. See
also Pentium, x86.
chip: See integrated circuit.
CHKDSK: A program (supplied with Windows NT, Windows 2000, Windows XP, and Windows Server
2003) that checks the integrity of a disk and corrects disk errors such as lost clusters. See also scandisk.
client: In a computer network, a computer that uses the services of another computer, called a server. For
example, a client can “ask” a server to provide it with needed data, or to print a file for the client. See also
server, workstation.
cluster: Smallest addressable unit of space on a disk. A one-byte file will actually use a cluster of disk space.
The minimum size of a cluster depends on the size of the disk volume. The FAT file system allows a maximum
of 65,536 clusters per volume, which means that the cluster size on a 64-megabyte disk volume is one kilobyte,
while a 128-megabyte volume uses two-kilobyte clusters. Thus, the FAT file system can be very wasteful of
disk space on large volumes. The NTFS file system does not suffer from this limitation.
COM: Acronym for Component Object Model, a specification developed by Microsoft for building software
components that can be made into programs or add functionality to existing programs running on Microsoft
Windows platforms.
component: A small modular program that performs a specific function and is designed to work interactively
with other components and applications. See also applet, COM.
contiguous: Adjacent; placed one after the other. A contiguous file is not fragmented; that is, it takes up a
single “chunk” of disk space. See also fragmentation, defragmentation.
control file: A file (Diskeep.ctl) used by Diskeeper to keep track of and control scheduled defragmentation of
disk volumes. See also Set It and Forget It.
controller: A specialized electronic circuit, which serves as an interface between a device, such as a disk drive,
and a computer. See also IDE, SCSI.
CPU: see central processing unit.
data: Information, as processed by a computer. Plural of the Latin word datum, meaning an item of
information.
database: A collection of related information about a subject, organized in a useful manner that provides a base
or foundation for procedures such as retrieving information, drawing conclusions, and making decisions.
datum: Singular of data.
defragmentation: The reduction or elimination of fragmentation, by making files and/or free disk space more
contiguous.
device: A machine, such as a printer or a disk drive.
digit: From Latin “digitus,” meaning finger. Any of the numbers 0 through 9 in the decimal number system,
called a digit because people originally used their fingers for counting. Computers use a binary number system
with only two digits (0 and 1).
directory: A file that contains a catalog of files and other directories stored on a disk, which allows you to
organize your files into groups, making them easier to find.
directory consolidation: A Diskeeper feature which, at boot-time, gathers (almost) all directory entries on a
disk volume into a single area on the disk, instead of scattered in many places. Directory consolidation makes
defragmentation more effective than it would otherwise be. Directory consolidation requires sufficient
contiguous free disk space into which the directories can be moved.
disk drive: A device containing one or more disks, treated as a unit by a computer.