Web proxy server is a method of defeating blocking policies implemented using varius security systems in the internet. Its a advance  web-based page that takes a site that is blocked and "tunnels" it, allowing the user to view blocked pages.

Advantages -

• Users are able to access blocked sites (games, chatrooms, messenger,social networking, etc.)
• Allow access to country-specific services, so that Internet users from other countries may also make use of them.
• Typically difficult to track, open proxies are especially useful to those seeking online anonymity.