Description

A firewall is a computer network security system that restricts internet traffic in to, out of, or within a private network.

This software or dedicated hardware-software unit functions by selectively blocking or allowing data packets. It is typically intended to help prevent malicious activity and to prevent anyone—inside or outside a private network—from engaging in unauthorized web activities.

Firewalls can be viewed as gated borders or gateways that manage the travel of permitted and prohibited web activity in a private network. The term comes from the concept of physical walls being barriers to slow the spread of fire until emergency services can extinguish it. By comparison, network security firewalls are for web traffic management — typically intended to slow the spread of web threats.