Many Windows and Mac computers have a firewall built in, but a firewall is just one part of security software. The Norton Smart Firewall monitors incoming and outgoing traffic, and works together with the Network Intrusion Prevention System (IPS) to inform the firewall about what “good” and “bad” traffic to allow or block. Because it looks at communications between your computer and other computers on the Internet, it protects your computer by: Warning you if other computers or programs on your computer attempt to connect to other computers. Cloaking inactive ports (where internet traffic comes in), providing protection against hacking techniques that use them. Monitoring network traffic coming into and going out from your computer for suspicious behavior, and blocking attacks before they intrude onto your system. While a built-in firewall in a computer is one step toward security, security software that includes a firewall provides much more thorough protection against all sorts of threats like malware, viruses and intrusions.