Why you need a Firewall?

Of course you dont need a firewall. But your computer need a firewall, if your PCs are networked .

A firewall is fundamental to personal computer security. Without a firewall, your computer is operating with an "open door" policy. Bank account information, passwords, credit card numbers, virtually any sensitive information on your computer becomes available to hackers. Hackers can get in, take what they want, and even leave one of their own "back doors" in place for ongoing access to your computer whenever they like.