How can a cache be used to improve performance when reading data from and writing data to a storage device?

A Cache is a term used in computer science to describe a component that stores data, so that when it is requested it can be accessed faster.

Caches are most commonly found in the form of a CPU cache, Disk cache and Web cache.

• CPU Cache

Memory located on the CPU, which acts faster and processes more swiftly, than that of a computer's main memory.

• Disk Cache

Unlike CPU caches which are controlled by hardware, a disk cache is managed by different pieces of software. For example a page cache will be controlled by the operating system known as Kernel.

• Web Cache

Possibly the most widely recognized type of cache, a web browser will use a cache to store information about passwords and web-pages etc.

This will ultimately reduce the amount of information that is required to be transmitted when surfing the Internet, and so improves responsiveness and makes the loading of websites quicker.

A Cache will have a faster transferring rate than that of most storage devices. This means data can be transferred much quicker than if it was sent from a normal storage device. Most importantly, a cache will not delete data once it has been used, instead it is stored in case the data is required to be used again.