proxy server is a server that acts as an intermediary for requests from clients and seeks 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.
HTTP Proxy – The HTTP proxy works with web browsers (HTTP clients) and servers that support HTTP. The HTTP proxy caches pages, or store them, for faster retrieval and are used occasionally to increase metadata services available on the website. Gateway Proxy – A proxy that allows requests and information to travel through without modification is called a gateway, or gateway proxy. T Content Filter – The filter that might be blocking the sites you wish to access is likely a form of a proxy as well. These specialized proxies called content filters require all requests to pass through for review. The content filter proxy then blocks requests that match requests on a "black list" or based on certain security settings. Depending on the complexity of the content filter, network administrators can add to or remove items from the black list. DNS Proxy - A DNS proxy server takes DNS queries from a ( Usually local ) networks and forwards them to an Internet Domain Name Server. It may also cache DNS records. Anonymous HTTPS proxy - Users wanting to bypass web filtering, that want to prevent anyone from monitoring what they are doing, will typically search the internet for an open and anonymous HTTPS transparent proxy. T Use of HTTPS proxies are detectable even without examining the encrypted data, based simply on firewall monitoring of addresses for frequency of use and bandwidth usage.
TOR Proxy - Tor ( The Onion Router) is a system intended to enable online anonymity. Tor client software routes Internet traffic through a worldwide volunteer network of servers in order to conceal a user's location or usage from someone conducting network surveillance or traffic analysis. Using Tor makes it more difficult to trace Internet activity, including "visits to Web sites, online posts, I2P anonymous proxy - The I2P anonymous network ( I2P ) is a proxy network aiming at online anonymity. It implements garlic routing, which is an enhancement of Tor's onion routing. I2P is fully distributed and works by encrypting all communications in various layers and relaying them through a network of routers run by volunteers in various locations. By keeping the source of the information hidden, I2P offers censorship resistance. The goals of I2P are to protect users' personal freedom, privacy, and ability to conduct confidential business. Each user of I2P runs an I2P router on their computer (node). The I2P router takes care of finding other peers and building anonymizing tunnels through them. I2P provides proxies for all protocols (HTTP, IRC, SOCKS, ...).