In computing, a cache is a place to store something temporarily. Active data is often cached to shorten data access times, reduce latencyand improve input/output. Because almost all application workload is dependent upon input/output operations, caching is used to improve application performance.
For example, Web browsers such as Internet Explorer, Firefox, Safari and Chrome use a browser cache to improve performance for frequently accessed web pages. When you visit a web page, the files your browser requests are stored on your computing storage in the browser's cache. If you click "back" and return to that page, your browser can retrieve most of the files it needs from the cache instead of requesting they all be sent again. This approach is called read cache. It is much faster for your browser to read data from the browser cache than to have to re-read the files from the web page.