In computer networks, a proxy server is a server (a computer system or an application) that acts as an intermediary requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server and the proxy server evaluates the request as a way to simplify and control its complexity. Today, most proxies are web proxies, facilitating access to content on the World Wide Web.
An open proxy is a forwarding proxy server that is accessible by any Internet user. Gordon Lyon estimates there are \"hundreds of thousands\" of open proxies on the Internet. An anonymous open proxy allows users to conceal their IP address while browsing the Web or using other Internet services. There are varying degrees of anonymity however, as well as a number of methods of \'tricking\' the client into revealing itself regardless of the proxy being used.