Firewalls and proxy servers are both an integral part of network security. In a way, they are similar in that they restrict or block connections to and from your network, but they do this in different ways.

Firewalls block ports and programs that try to gain unauthorized access to your computer, while proxy servers basically hide your internal network from the Internet. In a sense, it acts as a firewall, preventing your network from being exposed to the Internet by redirecting web requests when necessary.

What is a proxy server?

A proxy server is a computer system that acts as an intermediary between requests made by users. This type of server helps prevent attackers from attacking the network and is used as a tool for creating firewalls.

The etymology of the word proxy means "a number that can be used to denote the value of something," which means that a proxy server acts on behalf of or on behalf of a user. The fundamental purpose of a proxy server is to protect the direct connection of Internet users and resources.

How does a proxy server work?

An IP address is like a home address near you. Like snail mail, it addresses the delivery of the mail. Likewise, the Internet knows how to use IP addresses to send data to the correct computer on the network. A proxy server is a computer that uses an IP address to connect to the Internet. When you want to visit a specific site, you are sending a web request which is first sent to a proxy server. This request will be evaluated by the proxy server and the request to the site will be forwarded to the web server on your behalf.

• When a proxy server forwards your web request, it makes some changes to the data you send, but still gives you what you expect to receive.

• The proxy server will change the IP address so that the web server does not know the exact location. Proxy servers also encrypt data.

• Once data is encrypted, it is useless to others, but not to the actual recipient of the data. The proxy server uses cryptographic calculations such as AES or RSA.

• Once the request is evaluated by the web server, the proxy server collects the response and forwards the web page data on your side through the web browser. Proxy servers can block access to specific web pages based on IP addresses.

What is a firewall?

A firewall is a software or application that protects a computer or device's local network by restricting or blocking access by some unauthorized users located outside the network. It works at the IP packet level and can filter packets entering the private network. Packets can only enter the network if the firewall allows it. In other words, a firewall acts as a comprehensive barrier for monitoring, protecting, and auditing the local computer network from external security threats.

How does a firewall work?

Administrators set specific access control policies or rules to manage which packets are allowed and which are not. These rules are called access control lists. The list can contain allowed and denied port numbers, as well as the Internet protocol and IP address used by the request. In addition, you can customize this list, and network administrators can control not only what can enter the network, but also what can leave the network. This is how firewalls keep private networks safe.

• The firewall can monitor all incoming traffic. A two-way firewall can also monitor existing data and encrypt it.

• Firewalls restrict Trojans from locking your computer files and causing damage to the entire network.

• It can prevent hackers from entering your network.

• It reduces the risk of keylogging. By keylogging, we mean that keyloggers on the internet can monitor your dormant keystrokes and then use that information to repeat the same action. By doing this, they can log into your private account and possibly harm you.

What is the difference between a firewall and a proxy server?

Basic Firewall vs Proxy：

The major firewall and proxy difference are that firewall monitors and filters all incoming and outgoing access requests on a local network.While a proxy server mediates and connects a local computer with a server to retrieve data on the behalf of a user.

Purpose：

Firewall Server Unauthorized access is strictly not allowed.Proxy Server provides connections over the network. 

How and what do they filter：

The access requests are filtered based on the IP packets of the incoming traffic. Firewall Server blocks programs and ports that try to gain unauthorized access.

An organization can ban a certain website from using it. So a proxy server filters such websites for users. It also masks your local computer network from the Internet. This brings out another prime proxy and firewall difference.

Network layer：

The firewall server works on the network and transport layer data.

The proxy server works on the application layer data also.

Place of application or existence：

The firewall server is an interface between private and public networks.

The proxy server may exist on both sides with public networks.

Protects from：

Another vital firewall and proxy server difference is that a firewall protects the internal network from malicious threats and attacks.

Overhead generated：

Between firewall and proxy server, the firewall generates more overhead. This is because it acts as a major source of authorization whether a particular request can dive into a network or not.The proxy server generated here is less because it uses caching and receives a lesser number of requests.