What exactly is a proxy server? What does it do? Thedictionary defines proxy as the authority or power to act for or on behalf ofanother. That’s exactly what a proxy server does. Proxy servers areimplemented on networks that connect to the Internet, through a dial-upconnection or otherwise. For the clients on the network, the proxy serverrepresents the Internet (or at least a microcosm of the Internet), and to theInternet, the same proxy server acts on behalf of all the clients on thenetwork. Let’s see how this works.

A proxy server is installed on the network, at or near itspoint of connect to the Internet. It intercepts all requests to the Internet forWeb pages, etc, and tries to fulfill them locally. If it doesn’t have the pagein local storage (called cache), then it fetches the page from the Internet. Theproxy server stores a local copy of all such pages, and the next time someonerequests the same page, it serves the page from its local storage rather thanfetch it again from the Net.

What are the advantages of having such a setup?

For starters, a proxy server makes Internet access faster.How? Consider an office with say a hundred people. Chances are that most of themwould be visiting the same pages again and again. If the proxy server saves suchpages locally, then people requesting for those pages again will not have towait for the pages to travel to them all the way from servers located half theworld away. They will be able to access them instantaneously over the localnetwork.

This leads us to the second benefit of having proxy servers—conservingbandwidth. If the requested page is served off a local machine (the proxyserver) then you will not use already scarce bandwidth to download that page.So, other applications or page requests that can’t be satisfied by the proxyserver and have to actually go out to the Internet, get more bandwidth and, inturn, become faster themselves.

The third benefit of installing a proxy server is thatadministrators need not go and configure hundreds of systems for access rights.For example, if you want to avoid access to certain functionalities, saydownloading of streaming music and movies, you can easily do that at the proxyserver than by, say, sending out ineffective circulars.