In networking what is proxy?

hey,
I want to know what do you mean by proxy in networking?

A proxy is a server that sits between a client application, such as a Web browser and a real server. When a client application sends a request, it intercepts all requests to the real server to see if it can fulfill the requests itself. If not, then 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 A and user B access the World Wide Web through a proxy server. First user A requests a certain Web page, (say Page 1). Sometime later, user B 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.
This is a much faster operation, since the proxy server is often on the same network as the user.

Real proxy servers support hundreds or thousands of users.

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.

Well, the proxy servers also allows you to surf and browse the Internet or even specific sites without directly connecting with the destination site you want to. By utilizing this method, you will be able to surf secretly such that the destination sites will not see any requests or log entries from your IP address, but from the IP address of one of the proxies'. This can be achieved if have a proxy network.