Firewalls serve as a first line of defense to external threats, malware, and hackers trying to gain access to your data and systems.In its simplest terms, a firewall is like a virtual bouncer. It provides protection between the computer and…well, everything else. Let’s start with a little internet 101. Whenever you use your computer to visit a website, you’re connecting to another type of computer: a web server. And since servers are, essentially, computers, they’re vulnerable to the same types of attacks that your personal computer is.