What is Cache?


A cache is a component that improves performance by transparently storing data such that future requests for that data can be served faster. It can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching.
Web browsers and web proxy servers employ web caches to store previous responses from web servers, such as web pages. Web caches reduce the amount of information that needs to be transmitted across the network, as information previously stored in the cache can often be re-used. This reduces bandwidth and processing requirements of the web server, and helps to improve responsiveness for users of the web.
As of 2009, modern web browsers employ a built-in web cache, but some internet service providers or organizations also use a caching proxy server, which is a web cache that is shared between all users of that network.

Difference of Cache from Buffer
The terms "buffer" and "cache" are not mutually exclusive and the functions are frequently combined; however, there is a difference in intent.A buffer is a temporary memory location, that is traditionally used because CPU instructions cannot directly address data stored in peripheral devices. Thus, addressable memory is used as intermediate stage.
Also a whole buffer of data is usually transferred sequentially (for example to hard disk), so buffering itself sometimes increases transfer performance or reduce the variation or jitter of the transfer's latency as opposed to caching where the intent is to reduce the latency.
A cache also increases transfer performance

6 comments:

JospehCra威廷 said...

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政儒 said...

真正的愛心,是照顧好自己的這顆心。 ..................................................

廖淑凡 said...

君子立恆志,小人恆立志。..................................................

家信 said...

愛情是一種發明,需要不斷改良。只是,這種發明和其他發明不一樣,它沒有專利權,隨時會被人搶走。..................................................................

宛齊陳 said...

第一次睇你blog,鐘意! .................................................................

博行 said...

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