What is a Firewall?

Among the things that you can do to protect your computer from malware like viruses and spyware is a firewall. What exactly is a firewall and how does it help protect your computer? Learn about the essentials and how a firewall works here in this post.


A firewall is a system that monitors and controls everything that goes in and out from your computer, based on security rules. A typical use for a firewall would be between your computer and the internet where the firewall acts as a filter and prevents unwanted traffic and access to your computer. It can help prevent hacking attacks or the infiltration of your computer with malware without your knowledge.

There exist two types of firewalls, host based firewalls that run on your computer and network based firewalls, like the firewall which is most-likely built into your router. Both types have essentially the same purpose, to monitor and filter network traffic for more security.


Modern operating systems like Windows often come with a firewall built in. The firewall allows you to set up various security rules like what programs on your computer would be allowed to communicate with the outside and what type of connections would be permitted to your computer from the internet. If you have such an operating system like the latest versions of Windows, it is highly recommended that you use the included firewall for added protection.


Firewalls often also come as an added functionality with modern anti-virus and anti-spyware software programs. This means that as long as you have the anti-virus software running (which you should always do), there will be an additional layer of security from this firewall.

Practically, what such a software firewall does is that it notifies you any time when a program tries to connect to the outside or when it detects any suspicious activity. This gives you more control and more security against malicious attacks on your computer. The firewall will likely have some options so you can customize its security settings, but it should already provide adequate protection if you keep it at default settings.

While a firewall cannot provide 100% protection from malware and cyber criminals, it is a useful and recommended added layer of security that helps to protect your computer.

When you get a modern anti-virus program, make sure it provides firewall functionality for optimal protection!