What Is A Firewall (And How They Keep You Safe)

Firewalls are an essential part of any network infrastructure.

If you’re in any way familiar with cybersecurity and how to keep your data secure, you’ve probably heard the term firewall fairly commonly.

But what exactly is a firewall, and how do they protect you from threats online? In this article, we’ll take a look over what a firewall is, how they work, and some of the risks they help to prevent.

What Is A Firewall?

What Is A Firewall (And How They Keep You Safe)

A firewall is a piece of software that runs on your computer and protects it from outside threats. It’s the first line of defense against viruses, malware, and other malicious programs.

Firewalls also help protect you from being hacked by keeping your connection secure and private.

Firewalls examine all incoming network traffic and block any connections that are suspicious or unsafe.

For example, if someone sends an email to your computer, your firewall will examine the contents of the message and decide whether it should be allowed and if there is any malicious software within the email and any links it contains.

Think of a firewall like a bouncer at a club; if any unwanted traffic tries to access your devices, the firewall will stop it at the door.

Typically, a firewall will work in the background and you won’t even know it’s running unless it encounters or stops a threat.

In this case, you’ll be notified (typically through a pop-up or by closing the program) and the firewall will prevent the threat from affecting your device.

Firewalls are an indispensable tool that helps keep you and your device safe from harm. While online threats can be concerning, using a firewall greatly reduces the risk of any unwanted issues to your cybersecurity.

How Does A Firewall Work?

So now that we’ve taken a look at what a firewall is, how do they actually work? Let’s take a closer look.

Firewalls analyze incoming network traffic by using certain rules. All traffic coming into your devices will be subjected to this scrutiny, and will either be allowed through or flagged and restricted based on whether it conforms with these rules.

When a file or program tries to run on your device (for instance, if you open a link or access a new webpage), the firewall will take a look at it first.

What Is A Firewall (And How They Keep You Safe)

By examining the credentials and sources of the network, along with various other factors based on its configuration, the firewall can see whether it can be trusted or if it’s an unsafe connection.

If your connection isn’t secure, the firewall will block your access to prevent any malware from affecting your device.

Likewise, the firewall can screen and block the access of incoming connections as well.

Networks and connections that aren’t secure and could pose a threat to your device will be filtered out and have their access blocked to prevent them from transferring any unwanted malware or viruses before they even get the chance.

Depending on the configuration of the firewall, it may automatically block any unknown or unidentified sources to ensure a higher level of internet security.

Firewalls won’t protect you from every cybersecurity threat, however. Some hackers use methods that bypass firewalls entirely, so some may still be able to access your device without detection.

Additionally, firewalls aren’t completely foolproof, and sometimes they can allow dangerous connections through when they shouldn’t.

Physical cybersecurity breaches (including malware downloaded from a USB, or someone accessing your computer in person) also won’t be prevented by a firewall as these aren’t threats a firewall is designed to protect against.

However, most modern firewalls are extremely effective at protecting against many types of cyberattacks.

Using a firewall is a great first line of defense against these cybersecurity threats, and (when combined with other protective software like anti-virus) will give you much more peace of mind when using your devices.

Types Of Firewalls

There are several different varieties of firewalls, and each type has its own purposes. Here are some of the most common types of firewalls that you might encounter.

Hardware Vs Software Firewalls

Firewalls come under two categories: hardware firewalls and software firewalls.

Hardware firewalls, as the name suggests, are physical pieces of hardware that form a gateway for things entering your network.

These can be a broadband router that requires authentication, or an additional piece of equipment that you install onto your router or even the device itself.

A software firewall, meanwhile, is an internal piece of software that works to protect you from cybersecurity threats within your device.

Both of these types of firewalls are useful in their own right, and you’re best off combining the two varieties for maximum security.

Packet-Filtering Firewalls

A Packet-Filtering Firewall is a simple form of firewall that is best suited for small and/or personal networks.

It works by blocking certain types of traffic coming into your network based on its source, IP address, and port. This is only a basic form of firewall, and it won’t protect you from all forms of cyberattack.

Circuit-Level Gateways

These are similar to packet-filtering firewalls, but they use stronger forms of security to better determine whether traffic is harmful or not.

By using a ‘handshake’ to check whether something requesting access is legitimate, a circuit-level gateway can help filter out unsafe and untrustworthy traffic.

Network Address Translation (NAT)

An NAT only allows access to inbound traffic if you’ve specifically requested it.

Any other form of incoming network traffic is restricted until you give it access, making NATs great at reducing the risk of downloading or opening unwanted malware onto your devices.

Why Do You Need A Firewall?

We’ve already covered some of the threats a firewall helps protect you from and how it goes about doing so, but is getting a firewall really necessary?

To put it bluntly – yes, firewalls are a crucial part of your cybersecurity and without one you run the risk of exposing yourself to cyberattacks.

Without a firewall, your network essentially becomes open access; this means that anyone who can connect to your network is free to access your data, install malware and viruses, and can access or alter your personal information.

Firewalls also prevent malware from corrupting and deleting data from your devices, which can be difficult (or even impossible!) to recover. Having a firewall greatly reduces the risk of this happening.

Final Thoughts

Now that you know a little more about what a firewall is and how it protects you, you should have a good idea of why you need one.

Firewalls are a great tool for keeping you safe online, and are one of the best ways to ensure your cybersecurity doesn’t get compromised. 

Dale Williams
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