[QGLUG] what is a proxy server ?

[Mostaqeel]

proxy server

A server that sits between a client application, such as a Web browser,
and a real server. It intercepts all requests to the real server to see
if it can fulfill the requests itself. If not, it forwards the request
to the real server.
Proxy servers have two main purposes:

Improve Performance: Proxy servers can dramatically improve performance
for groups of users. This is because it saves the results of all
requests for a certain amount of time. Consider the case where both
user X and user Y access the World Wide Web through a proxy server.
First user X requests a certain Web page, which we'll call Page 1.
Sometime later, user Y requests the same page. Instead of forwarding
the request to the Web server where Page 1 resides, which can be a
time-consuming operation, the proxy server simply returns the Page 1
that it already fetched for user X. Since the proxy server is often on
the same network as the user, this is a much faster operation. Real
proxy servers support hundreds or thousands of users. The major online
services such as Compuserve and America Online, for example, employ an
array of proxy servers.
Filter Requests: Proxy servers can also be used to filter requests. For
example, a company might use a proxy server to prevent its employees
from accessing a specific set of Web sites