Last Updated: 01/24/2008

A computer firewall acts just like the firewall in your car - it protects you.  The firewall in your vehicle protects you from heat and fumes, your computer firewall protects you from malicious software & hackers.

There are two main types of firewalls in the computer world - a software firewall and a hardware firewall.  Software you install on your computer and it is more vulnerable because software always is (especially on Windows PCs).

A hardware firewall is a stand-alone device that is installed on your home or office network and is dedicated to protecting your computers.  These are often combined or integrated with other devices such as routers and gateways.

A firewall can work in many ways, but mainly they watch over the communication going on between your computer and other computers on the local network (LAN = local area network - your house) or on the wide network (WAN = wide area network - the Internet).

My favorite program, ZoneAlarm, will ask you each time a new program tries to "go out", or access the Internet, as well as each time something tries to "get in", or communicate with you from the elsewhere.