Understanding Internet Firewall

Many beginner computer users do not really understand the importance of firewall. It is easier for a not so savvy computer user to understand antivirus and antispyware software than the firewall because the name "firewall" is somewhat misleading.
A firewall is a program or software that prevents malevolent attacks coming from the internet from penetrating your computer or network. There are millions of "zombie computers" in the net that are all the time scanning for other computers connected to the internet that have security holes. Without a firewall, a computer that is connected to the internet is highly vulnerable to attacks and can be infected within twenty minutes. A firewall's function is to filter incoming internet data, preventing those that are known to be malicious from gaining access. The firewall works by "plugging" the "security holes" where malicious attacks usually get through.
Windows XP has a built in firewall, the Windows Firewall. You can configure it through the Control Panel but its default settings are probably the best settings you can have. Setting the firewall security too high could prevent or filter out clean traffic from entering your computer.
The best antivirus software like Eset Smart Security, AVG Internet Security, Kaspersky Internet Security, and Avast Antivirus Pro has built in firewalls. When you install any one of these security software in your PC, you need to turn off Window Firewall because it is not advisable to run two firewalls at the same time. So you have to choose between using the firewall that comes with your antivirus software or using Windows Firewall. Windows Firewall actually works as good as firewalls from third-party software.
Once your firewall is configured and turned on (you will know when Windows Firewall is not on because a warning icon and message will appear on your taskbar) you can literally forget about it; no need to baby sit it because it works almost independently in the background. Some firewalls like the one that comes with AVG Internet Security every now and then prompt you to decide whether to allow or block a particular traffic from gaining access to your PC. This usually happens when you are updating a newly installed software that are not yet in the "trusted list" of the firewall.
Having a firewall is one of the most important computer security measures that you can take.