Novices to the network world should check out the educational animated movie at the Warriors of the Net site. The Computer Networking section of WebJunction has many resources dedicated to understanding computer networks in libraries.
The Internet is a dangerous place filled with a constant barrage of automated scans that scour the Internet for vulnerable targets. Once identified, these targets receive a variety of attacks. Many of the attackers have no idea who owns the target, and the ultimate goal depends on both the attacker and the type of target. Selecting an appropriate firewall helps protect your network from the Internet and the Internet from your network.