Firewall

• A firewall is a software program or piece of hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the Internet.
• If you use a computer at home, the most effective and important first step you can take to help protect your computer is to turn on a firewall.

• The below figure shows the firewall alert from unknown application in your computer.

Hardware firewall

• If you have more than one computer connected in the home, or if you have a small-office network, it is important to protect every computer.
• You should have a hardware firewall (such as a router) to protect your network, but you should also use a software firewall on each computer to help prevent the spread of a virus in your network if one of the computers becomes infected.
• See figure it will not open the site because the system not allowing this site.