All firewalls are not created equal. To understand that, you need to know what the idea behind a basic firewall is. A firewall from the IT perspective is some hardware or software implementation that is meant to restrict incoming or outgoing network traffic. Most desktop operating systems as well as servers have some sort of firewall protection already built into the operating system. While these type of firewalls protect the machines they are running on, hardware firewalls/appliances will protect these machines as well as the rest of the hardware that exist on the network.