What Is the Purpose of a Firewall?

If you know how to use a computer firewall right, it can keep your computer safe by setting up filters that can find and stop hackers who try to get in through the Web or any other network, public or private. Firewalls can also keep track of and log attempts to get into the network, which is another way they protect it.

What Is the Purpose of a Firewall
What Is the Purpose of a Firewall

Firewall defined

A firewall is a network security device that monitors incoming and outgoing network traffic and allows or rejects data packets in accordance with a set of security rules. The firewall’s objective is to create a barrier between your internal network and incoming traffic from other sources (such as the internet) in order to filter dangerous traffic such as viruses and hackers.

How do firewalls Work?

Firewalls examine incoming traffic based on predefined rules and filter traffic from unsecured or suspect sources to avoid attacks. At a computer’s entrance point, known as ports, where information is shared with external devices, firewalls monitor traffic. For instance, “Source address is permitted to communicate with destination over port 22.”

See also : How To Turn on The Firewall in Windows 10

Consider IP addresses as residences and port numbers as individual rooms. Only trusted individuals (source addresses) are permitted to enter the house (destination address). Once inside, only the owner, a child, or a guest are permitted access to particular rooms (destination ports). The owner has access to all rooms (ports), but only selected rooms are accessible to children and guests (specific ports).


Intruders can be stopped by firewalls that look for strange words, domain names, or IP addresses. Blocking certain protocols like FTP, ports, or routing through a proxy service are other ways to do this.

Types of firewalls

Software or hardware firewalls are acceptable, though it is preferable to have both. A software firewall is a program placed on each computer that controls traffic through port numbers and programs, whereas a physical firewall is a piece of hardware located between your network’s gateway and the Internet.

The most prevalent sort of firewall, packet-filtering firewalls, analyse packets and prevent their passage if they do not meet a predefined security rule set. This sort of firewall verifies the source and destination IP addresses of the packet. If packets match a firewall’s “allowed” rule, they are permitted to enter the network.

There are two types of packet-filtering firewalls: stateful and stateless. Stateless firewalls analyse individual packets independently and lack context, making them ideal targets for hackers. Stateful firewalls, on the other hand, remember information about previously passed packets and are regarded as significantly more secure.

While packet-filtering firewalls can be successful, they ultimately provide very basic protection and can be quite limiting; for instance, they cannot assess if the request’s contents would have a negative impact on the application it’s attempting to contact. If a malicious request from a trusted source address resulted in the deletion of a database, for example, the firewall would have no means of knowing that. Proxy firewalls and firewalls of the next generation are better suited to identify such threats.

Different Types of Firewalls

Next-generation firewalls (NGFW) combine classic firewall technology with extra features such as encrypted traffic inspection, intrusion prevention systems, and anti-virus software. It covers deep packet inspection in particular (DPI). Deep packet inspection examines the packet’s data, allowing users to more efficiently identify, categorize, or block packets containing harmful material. Here you may learn about Forcepoint NGFW.

Proxy firewalls filter application-level network traffic. In contrast to standard firewalls, the proxy serves as a middleman between two end systems. The client must send a request to the firewall, which then evaluates the request against a set of security rules and determines whether it is allowed or denied. Proxy firewalls monitor layer 7 protocols, such as HTTP and FTP, and use both stateful and deep packet inspection to detect malicious traffic.

Network address translation (NAT) firewalls enable numerous devices with distinct network addresses to connect to the internet using a single IP address while concealing their separate IP addresses. As a result, attackers that scan a network for IP addresses are unable to obtain precise details, enhancing network security. Comparable to proxy firewalls, NAT firewalls function as an intermediate between a group of computers and external traffic.

Stateful multilayer inspection (SMLI) firewalls filter packets at the network, transport, and application levels by comparing them against trusted packets that are already known. Similar to NGFW firewalls, SMLI examines the entire packet and only allows it to pass if each layer is successfully traversed. These firewalls inspect packets to determine the status of the communication (thus the name) in order to ensure that all initiated communication occurs only with trustworthy sources.

Advantages and Benefits of Firewall

Firewalls stop bad programs from getting into your computer and doing damage. Software firewalls add an extra level of protection. They also stop you from sending malware that is on your own computer to other people. Other benefits if you use Firewall :

  1. Traffic Observation
  2. Protection from Viruses.
  3. Protection against hackers.
  4. Installation is easy.
  5. Defense against Malware.
  6. Grouping.
  7. Virtual Interconnection.
  8. Enhanced Security


Firewalls are important for anyone who uses a network, especially the Internet. However, they can sometimes stop the transmission of data and programs that are meant to be sent.


If you use the Internet without a firewall, it’s like leaving your front door open and putting a sign on it that says “Rob Me.”