Cache
A space in your computer’s memory which stores Web pages you have visited.
When you use GO, BACK, or a link to move to another Web page, the browser first checks to see if that page is in cache, because displaying from cache is faster than calling a Web page from a web server.
A proxy server also acts like a cache for a main server. Good Web site design utilizes Cascading Style Sheets and reusable graphics to help speed load time by storing common web elements in cache. A proxy server also acts like a cache for a main server.