1. Another reason companies use proxy servers is that it helps them save valuable bandwidth. Proxy servers can compress traffic from the Internet, cache files and web pages, and even remove ads from web sites before they reach your computer. It allows companies to save bandwidth, especially when they have hundreds or thousands of employees visiting virtually the same popular sites (e.g., CNN, The New York Times, Wikipedia, etc.).
2. When a web page is visited, the proxy server can store it, and when the next person requests it, it first checks to see if the page has changed. If it does not change, it forwards the local copy rather than re-downloading the entire page. This saves the company bandwidth and makes the loading process faster for the next person who requests the same resource.