What is a Firewall?

A firewall is a network security technology that monitors and controls network traffic based on security rules setup by a businesses security team. A firewall establishes a barrier between a trusted internal network and an untrusted external network. The main purpose is to make sure that unwanted or unauthorized network traffic isn’t allowed into the internal network. Firewalls are considered a protective control, and are deployed by businesses as a first step to protect their networks and build out a security program.