Component  role         

Function

Examples

Origin server

It acts as the container or definitive source for the representation of resources being requested; it must be the ultimate recipient of any requests. It uses a server connector to receive and respond to requests.

Web servers (Apache Tomcat, Microsoft IIS)

User agent

This is the user interface for the end user. It uses the client connector to initiate the request and get the response.

Web browsers (Internet Explorer, Chrome, Lynx)

Proxy

This acts as an intermediary for requests from clients seeking resources.

CGI Proxy, CERN Proxy

Gateway

This involves reverse proxies providing encapsulation of services such as security (encryption), performance enhancement (load balancing), or data translation (compression).

Squid, NGINX