What is a firewall?
A firewall blocks or allows network data traffic. The determination to block or allow is based on a set of rules. Its function is to protect private networks or computers against intrusion from potentially dangerous outside networks or computers.
A network firewall blocks or allows traffic between a private network and a public network (in nearly all cases, the internet). A firewall that protects a single computer is called a host-based firewall, software firewall or personal firewall.
Why you need a personal firewall
The firewall built into most routers blocks a lot of malware, but often malware is disguised as "safe" content. A personal firewall is an excellent second line of defense against attacks and attempts to take over your computer.
Personal firewalls are designed for most computer users—not networking professionals—and can be easily configured and tuned to do what you want. The ESET personal firewall, for instance, configures itself automatically.
A personal firewall can allow or deny traffic to and from specific applications. For example, if malicious software is able to access your computer, a personal firewall can block it from infecting other computers on your network.
How the ESET firewall works
Checks all data
The firewall checks any inbound or outbound data packets as well as the sending or receiving application to see if they match any of the firewall's rules.
Blocks or allows
Based the rules, the firewall either passes the data packet through or blocks it. Depending on the settings, it can then issue an alert window or record the action in a log file.
Protects against infiltration by botnet malware and prevents spam and network attacks launched from the endpoint machine.
While the most current versions of Windows include a personal firewall, they don’t have the ability to allow or deny traffic based on the application. Nor do they offer the more-sophisticated intrusion-detection and Network Attack Prevention included with ESET products.