A computer firewall protects your computer by putting up a barrier to keep anyone from accessing your files when you are connected to the Internet.  The common term for this is " hacking " your system - but it is important to understand that in most cases, computers are hacked by malicious software, and not a specific person as has been made popular in the movies.  

Typically, an attack on your computer or attempted hack is carried out by an automated software application that is designed to search for holes in your security.  This is like a back door to your computer, and once penetrated, the software has complete access to your entire system including sensitive information such as bank records, passwords and even your family pictures and email.  Depending on the application, the software will either ferret out your information, or will report back to its owner that your system is vulnerable and their is a back door access available.   ( to read more about Firewalls, click here ) 

Recommended Firewall Software

Zone Alarm

Zone Alarm is an advanced firewall application widely thought of as the grand-daddy of all firewall apps.  Although the company has expanded into anti-virus and anti-spyware programs, their bread butter has always been firewalls - something they have proven to be very good at.   The ZoneAlarm Firewall blocks hackers from infiltrating your home PC by hiding your computer from unsolicited network traffic.  By detecting and preventing intrusions, ZoneAlarm  Firewall keeps your PC free from viruses that slow down performance, and spyware that steals your personal information, passwords, and financial data.