About the Personal Firewall security level settings
Anytime your computer connects to another computer the threat of invasion by an outside intruder exists. The more computers connected to your computer, the greater the threat and the higher the probability your computer will be singled out for an attack. Each time you connect to the Internet, there are millions of computers that can also connect to your computer.
Since different users have different needs, PC-cillin provides three levels of security. The High Security level offers maximum protection from outside attacks, while the Low Security level offers minimum protection. Unless you use your computer as a server (Medium), we recommend you use the default setting: High.
High (Default): Cloaking, Trojan backdoor blocking, and Firewall all enabled. This is the default and most secure setting. At this security level, your computer's entry points are invisible, and Trojan backdoor programs are blocked. In addition, a barrier filters and examines both incoming and outgoing Internet traffic. This setting is recommended for the expert Internet user that frequently visits many different Web sites, often transfers files online, and receives a lot of email from numerous accounts. Also recommended for users with always-on Internet connections. Do not use this security level if you use your computer as a server; choose the Medium security level.
Medium: Trojan backdoor blocking and Firewall enabled. Use this setting if you use your computer as a server. At this security level, Trojan backdoor programs are blocked, and a barrier filters and examines both incoming and outgoing Internet traffic. However, your computer’s entry points are visible and server-functions will function normally. These settings are also recommended for the casual Internet user who spends less time online, doesn't often transfer files, and only uses one email account.
Low: Firewall enabled. At this security level, a barrier filters and examines both incoming and outgoing Internet traffic. This level is recommended for users that rarely go online, don't transfer files over the Internet, and don't use email on their computer.
See also:
Enabling your Personal Firewall