Firewall and DMZ: what are they?

• A. A firewall blocks all traffic between networks.
• B. DMZ is a semi-secure zone hosting public-facing services isolated from internal network.
• C. DMZ is inside the internal network.
• D. A DMZ is a type of firewall.

Answer: (B)

Understanding how a firewall and a DMZ work together to protect a network helps explain why this description is correct. A firewall controls traffic between networks by applying rules that decide what is allowed and what is blocked; it enforces policies rather than simply blocking everything. A DMZ (demilitarized zone) is a separate, semi-secure network segment placed at the edge of the internal network to host public-facing services—like a web or mail server—so those services are accessible from the outside but are isolated from the internal network. This isolation means that if a service in the DMZ is compromised, the attacker doesn’t automatically gain access to internal systems. Importantly, the DMZ is not inside the internal network and it’s not a type of firewall; it’s a separate zone that is typically protected by firewalls on its boundaries.