Companies that want to sell security-related products and services will paint the Internet as Crime Alley, filled with sociopathic teenagers, Russian Mafia hackers and con artists working out of a deadly jungle of worms, viruses and Trojan Horses. Companies that aren't in the security business argue that there are no problems, which translated means they may not be eager to fix flaws in their programs. Alas, the truth lies somewhere in the middle. The Internet was created by and is used by people, some of whom are criminals. A firewall, which monitors your Internet connection and refuses to let anything suspicious in, can provide sufficient protection.
Firewalls come in hardware and software varieties.
Hardware firewalls are boxes that you plug your computer into. Many broadband routers and modems now come with built-in firewall protection. Software firewalls, like BlackICE Defender, are programs that you download from the Internet to your personal computer. It monitors your Internet traffic and compares what's coming in to what's permitted. Most firewalls are set to let Web pages and e-mail pass through, but won't let telnet or ftp requests in, unless the person has a password.