How Does a Firewall Work on a Computer?

How do firewalls work? Broadly speaking, a firewall is a defense mechanism to protect internet users from hacker attacks or from unwanted connections. That’s the outline, but what about the details?

How do firewalls work?

The firewall works as an intermediary for the activities you do on the Internet, it is in the middle as a filter which is good internet data and which is bad internet data.
how do firewalls work
The picture above is a simple illustration of how a firewall works, the blue line indicates that the connection is from a trusted source, and the red line is a connection from a hacker. Because of the existence of a firewall, the connection that reaches you is a connection from a secure source, and connections originating from hackers are stuck at the firewall.

Are firewalls important?

Firewalls are very important for those of you who often use the internet for daily purposes, without a firewall, it is possible that you will be more vulnerable to attack. Here I say that “important” is subjective, yes, maybe those of you who already understand what dangers are on the Internet prefer to turn off the firewall, because sometimes there are applications that cannot be used because they are blocked by the firewall. Moreover, suppose you are connected to public wifi, for example at airports, hotels, wifi corners, etc. The chances of meeting nosy people with connections will be greater.

How do I use apps that are blocked by a firewall?

The trick is to add the application that will be used or change the rules of the application in the firewall settings, for example as shown below.
how do firewalls work
It shows that I allow opera.exe and Opera Internet Browser to be accessible to the internet, whether it’s a private or public connection. It’s the same as when you want to allow an application that is blocked by a firewall, you only need to find its name there and check everything (private and public). But if the application you want to use isn’t there, you can add the application by clicking ” Allow another app ” and navigate to the application folder you want to use.

Firewall Types

Generally, firewalls are divided into 2 types, namely ” Host based firewall ” and ” Network based firewall “.

Host based firewall

This type is a type of firewall that uses applications, if you use windows, then the firewall must have been installed and turned on by default. Host based means that a firewall running on your computer will only protect that computer.

Network based firewall

Network based firewall is a firewall that operates even before your router device receives data that will be sent to your computer, and also other people who are connected using that router. So it is protective overall, the people who are connected to the router are more secure. By default, circulating routers already have a built-in firewall, just like computers that have Windows OS installed. But there are also hardware devices that are stand-alone for firewalls, for example, such as: But keep in mind that the price is not cheap, and most are usually intended for the security of a company.
Can you use host-based and network-based firewalls at the same time?
You can, and it’s better that way, because suppose the router’s firewall is breached, then you still have another security mechanism, namely the one on the computer, so it’s safer. Usually also the firewall on the computer is stronger, because we can specifically sort out which ones are good and which ones are bad manually, it is also common to find applications that are originally safe but cannot be accessed by the firewall because they are considered viruses, and most of this is false -positive (not a real virus).

How does a firewall work to determine what is good and what is bad?

The firewall determines good and bad connections based on reports from users who have previously been exposed to it and then enters the report data into a database owned by the firewall vendor, for example the built-in Windows firewall means the database used belongs to Windows. Windows defender or default Windows antivirus is integrated with Windows default firewall, and both of them are mutually sustainable about which choices are good and which are bad, this is explained on the official Microsoft website here Windows Defender Firewall with Advanced Security (Windows) – Windows security | Microsoft Docs .


Internet security is indeed important for internet users, whether it’s downloading files, or even just browsing, with the help of a firewall we will be calmer to surf the internet. Choose a trusted source if you want to download files, and if possible, avoid using pirated applications, guys! Because most cases of virus spread that occur are due to user errors in downloading pirated applications. Even for just downloading, surely some of you still use pirated IDM (Internet Download Manager), why use pirated when there are free applications that are similar and even better? Try FDM , I’ve been using it for years and the results are great! That’s an article about how a firewall works on a computer, if you have any questions, you can directly comment below and I’ll answer them, you can comment using Facebook too, you know 😀 Thanks for reading!
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