Firewall

A firewall protects the local network or local devices from unauthorised connections from the public Internet. It can consist of just software or a combination of software and hardware. The firewall function is able to monitor both incoming and outgoing data traffic and block or allow it as necessary. It captures data between an external (public) and internal (local) network or connection. In a private environment firewall functions are often implemented in the internet access router. However, downstream dedicated devices may also be used.