What is Firewall in Computer Network?

A firewall is a network security tool that monitors incoming and outgoing network traffic and determines whether to allow or block definite traffic based on a defined collection of security rules.

The primary purpose is to enable non-threatening traffic and avoid malicious or unwanted data traffic for protecting the system from viruses and attacks. A firewall is a cybersecurity device that filters network traffic and supports users to block malicious software from creating the Internet in infected computers.

Software vs Hardware Firewalls

Firewalls can be hardware or software. In addition to reducing access to a protected device and network, a firewall can chunk all traffic coming into or leaving a web and handle remote access to a private network by secure authentication certificates and logins.

Hardware firewalls

These firewalls are launched either as standalone products for corporate use or, more frequently, as a built-in element of a router or various networking devices. They are considered an essential element of any traditional security system and network setup.

Software firewalls

These are installed on a device or supported by an operating system or network device manufacturer. They can be customized and support a smaller level of control over functions and protection features. It can protect a system from standard control and access attempts but have trouble with more sophisticated network breaches.


There are various limitations of firewalls which are as follows −

  • Firewalls cannot stop customers from accessing malicious websites, making them vulnerable to internal threats or attacks.

  • Firewalls cannot save against the transfer of virus-infected files or software.

  • Firewalls cannot avoid the misuse of passwords.

  • Firewalls cannot protect if security rules are misconfigured.

  • Firewalls cannot assure against non-technical security risks, including social engineering.