What is a cache

A cache, pronounced CASH is hardware or software that is used to store something, usually data, temporarily in a computing environment. It is a small amount of faster, more expensive memory used to improve the performance of recently or frequently accessed data. Cached data is stored temporarily in an accessible storage media local to the cache client and separate from the main storage. The cache is commonly used by the central processing unit (CPU), applications, web browsers, and operating systems. The cache is used because bulk or main storage can't keep up with the demands of clients. Cache decreases data access times, reduces latency, and improves input/output (I/O). Because almost all application workloads depend on I/O operations, the caching process improves application performance.