What Is a Firewall and Why Do You Need One?
Firewalls are one of the most important network security systems you can have in place. They prevent cyberattacks, protect sensitive data and ensure privacy in a computer system or network. They also serve as the foundation of other network security systems, such as anti-virus programs and network intrusion detection systems.
A firewall creates a border between an external network and the network it guards by examining all data packets (pieces of data used for internet transfer) that enter or leave a network using pre-configured rules to identify whether each entry is benign or malicious. It then allows or blocks these data packets based on those rules.
Different types of firewalls use varied methods to examine data packets. For example, packet filtering firewalls examine data packets in isolation, which makes them easy targets for hackers, but stateful inspection firewalls can keep track of the context of each data packet and make better decisions. Similarly, proxy firewalls filter packets at the application layer of the standardized communications model, OSI.
You can find firewalls in both hardware and software. Most operating systems, including the OS you’re running on, include a built-in firewall that you should enable for added protection. Firewalls can also be purchased from local computer stores, software vendors or online from a reputable source.
The type of firewall you need depends on your network’s needs and size. A larger network will require a more complex and scalable firewall solution than a smaller, less demanding network.