1. A web proxy server (caching server) is a server on the local network that keeps copies of recently retrieved or often used web pages or parts of pages.
2. When the next person retrieves these pages, they are served from the local proxy server instead of from the Internet.
3. This results in significantly faster web access in most cases, while reducing overall Internet bandwidth usage.
4. When a proxy server is implemented, the administrator should also be aware that some pages are not cacheable.

Example:

Pages that are the output of server side scripts, or other dynamically generated content.