Anonymous proxy servers hide your IP address. It means that you do not give your IP address and effectively hide information about you. Even, the proxy did not allow anyone to know that you are surfing through a proxy server. Anonymous proxy servers can be used for all kinds of Web-services, such as Web-Mail (GMail, MSN Hot Mail, Yahoo mail), web-chat rooms, FTP archives, etc
There are many websites that provide anonymous web proxy. That is a web service that provides anonymous surfing or through their proxy servers. These websites have been created because so many people use it for their various needs. One of the utilization of the most commonly used is to open up access to certain websites that may be blocked by internet providers. So that, the users of their network can not access websites which are being blocked by them. Then, anonymous web proxy allows internet users to open blocked websites using their existing networks.