One of the simples but most important security measures for any computer to implement would be to properly setup a software or if financially feasible hardware firewall or both.

The main difference between hardware and software firewall is that hardware firewall is usually dedicated to a range of security services and it's well tested by the vendor to do it's job extremely fast and well. Software firewall usually comes for free with most current operating systems such as Microsoft's Windows XP, Vista as well as Linux & Unix Systems and others. Unfortunately such software firewall will have to share system's resources with the rest of programs that are installed and at times could be causing a significant performance loss to a system while filtering traffic.

Firewall monitors all the traffic based on the rules that the firewall administrator would setup such as:

• there may be a need to block certain websites to be accessed from any computer on the network
• or sometimes some software has to be blocked from access network from the outside such as spyware