What is Proxy Server?

Proxy server, which actually can be either an application program or a physical computer system, is defined in the computer networks world being a server which actually works or you may say functions on behalf of those clients, being an intermediary source, that seek some resources from different servers. Just like a client, sends request through a proxy server, to retrieve a file, web page, connection or any other available resource over the specific server, is the best example of proxy server usage.

Filtering rules of a proxy server actually helps this intermediary source to evaluate the request received from a client which is actually for a different server on a different network. For example, the traffic can be or may be filtered by the proxy server by protocol as well as by IP address.

If the clients request (received by this intermediary source) passes the filtering rules, then the relevant server is connected by this proxy (on the clients request or you may say clients behalf) just in intention to fulfill the requirements includes in the clients request. Optionally the clients request may also be altered by the proxy as well as the servers response may also be altered by this intermediary source.

Even sometimes the request is reverted back to the client by this intermediary source without touching or sending request to the relevant server. But in this case, responses are cashed by this intermediary source, that are received from the relevant or you may say remote server and then subsequent requests are returned directly with the same contents.