If you are a frequent Internet user, you have likely used or heard of proxy servers. Some of us might also have heard the terms forward proxy servers and reverse proxy servers. But what are they? How do they work? And how are they different from each other? Let’s try to understand that in detail.

What is a proxy server?

A proxy server is a server that works as an intermediary between a client requesting a connection or service and a server that provides the resources. All requests from the client, as well as the responses from the server, pass through the Proxy Server. It provides administrative control over the contents being relayed and hides the IP address of the host behind the Proxy Server at the same time.

How do proxy servers work?

Depending on how the Proxy Server functions, there are three main types of proxy servers:

• Forward Proxy Server
• Reverse Proxy Server
• Open Proxy Server

What is a forward proxy server, and how does it work?

A forward proxy server is a proxy server that provides proxy services to a group of clients that are mostly part of an internal network. When one of the clients in the internal network makes a connection request, the request passes through the forward proxy server. The forward proxy server looks at the request and decides whether the connection should proceed. And, based on that, a connection is made to the requested server providing the resources. The requested server cannot see the IP address of the requesting client in the internal network. It will view the connection as coming from the forward proxy server. The requested server will send a response to the forward proxy server, and the proxy server will then forward the response to the requesting client inside the internal network.

Why is a forward proxy server used?

There are a number of reasons for using a forward proxy server:

• A forward proxy server usually works with a firewall. So, it can control the traffic originating from a client in the internal network and ensure the security of the internal network.
• A forward proxy server acts as a single point of access and control of the clients in the internal network. As it can provide administrative control over the contents being relayed, it is easier to enforce security policies using a Forward Proxy Server.
• A forward proxy server helps hide the IP addresses of clients in the internal network, providing security to those clients.

What is a reverse proxy server, and how does it work?