Firewall

A firewall is a dedicated appliance, or software running on another computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules.” – Wikipedia Basically, a personal firewall is a piece of software that monitors all traffic that goes from your computer to another, via the internet or a network, and vice versa. It provides protection for your computer, as it prevents things that aren’t allowed in from getting into your computer and prevents things that aren’t allowed out from getting to another system. All of this is controlled by the user, as he/she chooses whether to give a program permission to pass through the firewall.

A firewall can be a Hardware or software based firewall. They both do the same thing. Protect your PC to outside intrusions. In order for your PC to access the internet it needs to have ports open also for email and chat and so on.

A Firewall monitors ports and does not allow incoming requests (like someone trying to gain acces to your PC via one of these ports). If you have a Router, this is also a firewall as it hides your PC’s IP address and assigns it a IP address of it’s own like 192.168.0.X The outside world (outside of your network) cannot see your PC’s true IP address and therefore cannot scan for open ports. If you have DSL or Cable internet it is recommended that you have a firewall of some sort.