Firewalls are inexpensive and some are free for home users. New firewall releases are becoming easier to use and offer user-friendly interface. Windows even comes with a free built-in firewall, and has since Windows XP.
There are essentially two forms of firewall that typical home user will frequently encounter. The first is a hardware or firmware firewall, which is usually found in a home router. This type of firewall is pre-configured from the factory to prevent unauthorized access of a wireless or wired network from intruders. It can be further customized by the user to block specific ports, which will prevent certain programs from accessing the Internet. You may also sometimes be forced to customize the router firewall to allow certain programs access to the Internet. PC games, for example, sometimes conflict with router firewalls.
Another common form of firewall is a software firewall, such as Zonealarm. A software firewall monitors Internet traffic going into and out of a specific PC. Should suspicious activity be noticed, it will be blocked, and in most cases a pop-up notice will alert whoever is using the PC. A software firewall can also be used to block or enable Internet access for specific programs, and the process of doing so is often easier than doing so via a router. Of course, the downside is that access will only be shut down for the PC that the software firewall is installed on.