There are many threats on the Internet - hacker activity, viruses, and worms. The ZoneAlarm Firewall protects your computer from most of those threats. It defines three security zones - Trusted, Public, and Blocked.

By default, the Public Zone works in High security mode, and the Trusted Zone works in Medium security mode:

• High security mode for Public Zone lets you connect to network resources, but prevents other unauthorized network users and computers from accessing the resources on your computer and compromising your computer protection. Unknown networks and most wireless networks, even secured wireless networks, should be in this High security Public Zone.
• Medium security mode for Trusted Zone protects your computer from possible attacks on Windows networking services, but lets you share resources with other computers on the network. Networks you know and trust, such as your home or business LAN and known protected wireless networks, should go in this Medium security Trusted Zone.
• Blocked Zone - contains computers and networks you distrust. No traffic to or from this zone is allowed.

The ZoneAlarm Firewall is on by default as soon you as install ZoneAlarm software. You do not need to do anything, unless you want to change the default configuration, or to turn it off temporarily ("Turning the Firewall On and Off"). To learn how to change the default Firewall configuration, see Managing Basic Firewall Zone Settings.