Proxy sites are the sites designed to give you access to the world wide web keeping your identity anonymous. basically when you visit any site from your PC , the web server gets to know your IP address, which can be used to track you or whatever. however if you visit the same site via a proxy site then your IP is not revealed to that web server. proxy server requests that page on your behalf, so IP of proxy server goes and then that page is sent to you by the proxy server.
Proxy server/sites are also used to bypass the parental control or firewall. Eg in colleges/schools if social networking sites are blocked then you can use a proxy server to request facebook/any other social networking site for you. in simple words if A cant connect to B then A sends to C , C sends to B and vice versa. thus proxy site acts intermediate
http://www.yourproxy-free.com/
