What is "disk cache"

n. a cache that stores copies of frequently used disk sectors in random access memory (RAM) so they can be read without accessing the slower disk

Disk cache may refer to:

• Disk buffer, the small amount of RAM embedded on a hard disk drive, used to store the data going to and coming from the disk platters
• Page cache, the cache of data residing on a storage device, kept by the operating systems and stored in unused main memory
• General application-level caching of the data residing on a storage device