A type of data compression
that works by storing compressed versions of files
on the hard disk
. A disk compression utility
sits between the operating system
and the disk drive
. Whenever the operating system attempts to save
a file to disk, the utility intercepts it and compresses it. Likewise, when the operating system attempts to open
a file, the disk compression utility intercepts the file, decompresses it, and then passes it to the operating system. Because all applications
access files through the operating system, disk compression utilities work with all applications. The entire process is transparent
to the user, though opening and closing files may take a little longer. On the other hand, a disk compression utility can double the amount of disk space available.
Windows comes with a built-in disk compression utility called DriveSpace. You can also purchase third-party disk compression utilities for Windows and other operating systems.