Browser cache
From ctowiki
Most modern web browsers utilize a cache of stored information to load pages faster. This cache is effectively a saved copy of web pages you have visited in the past. Since most web pages do not change more than once every few days, most people never notice that their computer is using old information instead of downloading the latest copy of a web page. by avoiding the need to download from the internet, often the slowest operation when displaying a web page, the time to display the page is greatly reduced.
This can cause problems, if the page has been changed recently, or if your cache contains an incorrect version of the web page. These problems are easily fixed by clearing your browser cache.