What Is a Firewall?

When you hear about computer security, there are some words that often come up: “antivirus”, of course, but also “firewall”.

But then, what is this a “firewall”?

It is actually a fire-wall, a wall that protects your computer from other devices that share the same network connection. It is often included in the best antivirus programs available on the Internet.

Let’s take a closer look at what does this “wall” do.

How the firewall works

The purpose of a firewall is to control the flow of information between your computer and the Internet. To do this, the firewall checks all of this information to see if it complies with its filtering rules; depending on whether it does or does not, the information will be allowed or denied access to your computer.

The firewall can therefore be as effective in preventing information theft from your system as any other type of intrusion.

Firewall filtering rules

The firewall will filter the flow of information converging on your computer according to the rules and criteria set by the editor, but also by yourself, if you wish to add some. Thus set, these rules will allow the firewall to :

• Select data considered confidential, such as your passwords, credit card numbers or other sensitive documents
• Prevent the communication of some of your personal information to websites, such as your email address or your country of residence
• Prohibit the websites you visit from depositing information on your device, such as cookies and other elements that can later trace your activity on the web

The risks of not using a firewall

As you may know, each connected computer has its own Internet address, which is a series of numbers that identify your connection.

Many hackers proceed by randomly scanning ranges of numbers corresponding to possible Internet addresses in the hope of detecting a flaw in one of them. The firewall – that bulwark, remember – prevents a vulnerability from being detected and even alerts you to a scan aimed at your computer.

However, it is important to specify that the use of a firewall does not exclude the use of an antivirus, which is the only tool capable of scanning your computer for malicious codes.

Firewalls and antivirus software go hand in hand, and when used together, they are the only tools that can effectively ensure the security of your device. Therefore, choose antivirus software that includes a firewall or install both!