i always asked myself .."why should someone use a firewall ?"
u always hear about firewall, when u r at home and use internet for some long time , and especially when u work for some large company u always hear about firewall. You often hear people in companies say things like, "I can't use that site because they won't let it through the firewall."

Breifly, u can use a firewall to protect your home network and family from offensive Web sites and potential hackers.

but "what is a firewall ?"
Basically, a firewall is a barrier to keep destructive forces away from your property. In fact, that's why its called a firewall. Its job is similar to a physical firewall that keeps a fire from spreading from one area to the next.

anyways , if somebody got some more infos about what's a firewall and how it works , please reply to this thread , thx