In computer networks, a proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers.HTTP proxy server is a proxy, allowing working on the Internet with HTTP protocols. It can carry out caching of information downloaded from the Internet.Let’s have a more detailed look over its abilities.
HTTP proxy servers have several anonymity levels.That may hides the original users’ IP address and other details from the remote server. It depends on purposes, which a proxy is used for, so an anonymity requirement is not always an essential one.
- Transparent – these proxies are not anonymous. They, first, let a web server know that there is used a proxy server and, secondly, “give away” an IP-address of a client. The task of such proxies, as a rule, is information caching and/or support of Internet access for several computers via single connection.
- Anonymous – these proxy servers let a remote computer (web-server) know, that there is used a proxy, however, they do not pass an IP-address of a client.
- Distorting – unlike the previous type, they transfer an IP-address to a remote web-server, however, this address is a phantom: randomly generated by a proxy server or any fixed (not your) IP. So, these proxies distort your IP address from the point of view of a web-server.
- High anonymous (elite) – they do not send your IP-address to a remote computer. Also, they do not inform that there is used any proxy server! So, a web-server “thinks” that it works directly with a client.
Source:
http://privateproxyreviews.com/httpproxies/
http://www.freeproxy.ru/en/free_proxy/faq/what_is_http_proxy.htm