Pronounced "disk cash." An area of computer memory where data is temporarily stored on its way to or from a disk.
When an application asks for information from the hard disk, the cache program first checks to see if that data is already in the cache memory. If it is, the disk cache program loads the information from the cache memory rather than from the hard disk. If the information is not in memory, the cache program reads the data from the disk, copies it into the cache memory for future reference, and then passes the data to the requesting application. This process is shown in the accompanying illustration.
A disk cache program can significantly speed most disk operations. Some network operating systems also cache other often accessed and important information, such as directories and the file allocation table (FAT).
See also directory caching.