FIREWALLS

What is a firewall?

A firewall is a security system designed to prevent unauthorized access from the Internet to or from your computer/network. A firewall works by screening out malicious traffic and attacks, the primary function being to let "good" traffic pass through while ‘bad’ traffic gets blocked. The most important part of a firewall is its access control features that distinguish between good and bad traffic.

When installed, a firewall exists between your computer and the Internet. The firewall lets you request web pages, download files, etc. while making sure other people on the internet can not access services on your computer like file or print sharing. Some firewalls are pieces of software that run on your computer. Other firewalls are built into hardware and protect your whole network from attacks.

Potential intruders can download dozens of programs from the Internet which scan huge ranges of IP address for vulnerabilities like file sharing services. These programs are easy to download and run. Almost no network knowledge is needed to use these programs to exploit or harm your computer.

Any decent firewall will keep you safe from these types of attacks, and everyone connected to the Internet should be running some sort of firewall.

There are links to free software firewalls under the "Free Products" heading on the page you just came from.