A firewall acts as a middle man between you and the internet
A firewall acts as a middle man between you and the internet. It looks briefly at the packets going into and out of your system, and gives each one a thumbs up or thumbs down verdict. (pass or block). This action helps prevent outside intrusion attempts on your system. Firewalls come in two forms: Hardware and software. Software firewalls operate on a system and run in the background monitoring your connection. The may be called "Personal Firewalls". Hardware firewalls are separate boxes that do the work of a firewall without taking system resources. Almost all routers contain at least a basic firewall functionality.
