Which of the following describes a system that enforces a boundary between two or more...

A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It establishes a barrier between a secure internal network and an untrusted external network, such as the internet. This system is designed to prevent unauthorized access to or from private networks and is a fundamental piece of a comprehensive security framework for any organization.

References: The concept of a firewall as a system that enforces a boundary between networks is well-established in cybersecurity literature. It is recognized as a critical component for protecting network resources by filtering traffic and blocking unauthorized access while allowing legitimate communication to pass123.