04/17/2026
Last week I had a conversation on LinkedIn with someone asking about firewalls.
More specifically, he wanted to know if he even needed one — because both his Mac and Windows computer already have built-in firewalls.
Now, I’ll be honest… when I get questions like that, I have to take a pause because I remind myself — this is what I do every day. Not everyone lives in this world.
So we started talking.
And to his credit, he’s genuinely interested and open to learning. As the conversation goes on, you can see it start to click — what a firewall is, what it does, and why there are different types.
So let’s break it down simply.
What does a firewall actually do?
A firewall controls what traffic is allowed in and out. Think of it like a gatekeeper — deciding what gets through and what gets blocked.
Computer-based firewalls (Mac/Windows):
These protect the individual device. They help control what that one computer sends and receives. They’re important — but they only protect that single machine.
Network firewalls (hardware devices):
These sit between your internet and your entire network. Instead of protecting one device, they protect everything — computers, phones, printers, cameras, and more. They also give you more control, visibility, and stronger protection overall.
Firewall as a Service (cloud-based):
This is protection delivered through the cloud. Instead of having all the hardware on-site, filtering and monitoring happen remotely. It’s becoming more common, especially for businesses that want flexibility without managing everything locally.
Residential firewalls:
These are showing up more in homes, and they’re actually pretty powerful. They sit between your internet provider and your home network, giving you control over what comes in. That can mean blocking malicious sites, limiting social media, restricting gaming services, or even setting time-based rules.
They’re not just about protection — they’re about control.
So back to the original question:
“Do I need a firewall if my computer already has one?”
The better question is:
“Do I want to protect one device… or everything connected to my network?”