A firewall is software or hardware that prevents hackers and some types of malware from gaining remote access to a computer over a network or the Internet. Its action is to check information received from the Internet or local network, and block or allow access to the computer.

A firewall is not the same as antivirus or malware protection software. A firewall provides protection against Internet worms and hacker attacks, antivirus software provides protection against viruses , and anti-malware applications provide protection against malware.

All of these types of applications are required on a computer. You can use the Windows Defender antivirus and antimalware software that came with Windows 8 or another antivirus that protects against malicious code.

It is sufficient to install one firewall application on the computer (except for the built-in firewall of the network router ). Using multiple firewall applications on a computer can cause conflicts and problems.

Windows Firewall is included by default.

This image shows how the firewall works:

How Windows Network Firewall Works

We recommend using the following firewall settings:

Firewall is enabled for all network connections.
The firewall blocks all incoming connections except those that cannot be denied.
Firewall is enabled for all types of networks (private, public or domain).
Note : Computers running Windows RT or Windows 8 operating systems cannot be joined to a domain. Domain joining is supported only for computers running Windows 8 Pro or Windows 8 Enterprise.

Turn Windows Firewall on and off
Do not turn off Windows Firewall if no other firewall is turned on. Disabling Windows Firewall can leave your computer (and your network, if present) more vulnerable to hacker or worm attacks.

For more information about: firewalls network security