When you connect to the Internet, you get connected with the largest network of computers spread worldwide. The Internet connection established on your laptop or desktop computer is a two way road, which allows programs installed on your computer to access web resources, while also allowing other web services on the Internet to access your computer resources. Hackers on the Internet can use this two way access to gain unauthorized access to your system resources. To prevent this, you need to have a firewall installed on your computer. An antivirus software is about computer security, while a firewall is devoted to Internet security.
The job of a firewall is that of a filter which controls what information is downloaded to your computer and transmitted by it. The user can control which software services are allowed access to the Internet and which aren't. It prevents unauthorized telnet and FTP connections from being established with your IP address. It prevents malware of computer viruses from accessing the Internet from your computer. It needs to ensure that no data is leaked out of your computer through any of the ports, used to connect with the Internet.
A firewall should prevent remote login sessions, SMTP session hijacking, denial of service attacks, email bombs and prevent the dangers arising out of application backdoors, source routing and redirect bombs. In conjunction with a good antivirus software, the firewall creates an effective bulwark against hacking attacks. By controlling the firewall settings, you can control the flow of information towards or away, from your computer. Let us take a look at some of the best Firewall programs which you could install on your Windows 7 system.