A firewall is a security system that protects a computer network or an individual computer from unwanted network access. More broadly, a firewall is also a sub-aspect of a security concept. Every firewall security system is based on a software component. The firewall software is used to restrict network access, based on sender or destination and services used. It monitors the traffic passing through the firewall and decides whether or not to allow certain network packets through based on set rules. In this way, it tries to prevent unauthorized network access.
