Cyber Lingo: What is a firewall?

This document provides a high-level overview of firewalls, including when and how they are used, their role in protecting networks and sensitive data, and basic guidance on identifying suspicious activity (e.g., via alerts and log reviews). It defines related security concepts like IDS, VPN, and antivirus, and references the 2013 Target breach as an illustrative example, emphasizing the importance of proper firewall configuration and monitoring for robust cybersecurity.