Proxy Server - A Proxy Server acts as an intermediary between an end-user (customer) and his/her server (content provider).  A Proxy Server can serve several purposes; it can hold the most commonly and recently used content for users, (versus users having to load up a new copy of the webpage everytime they visit it, which can be time and bandwidth consuming.) Also it can filter and convert content to match the capabilities of the receiving software and/or hardware.