What's the difference between Firewalls and DMZs? These terms seem to overlap at time and I'm not clear on the difference. Maybe a DMZ is achieved using firewalls?
Firewall is a device.sometimes it can be a software as well. DMZ is a Logical or Physical Network.
DMZ or demilitarized zone is a physical or logical subnetwork that contains and exposes an organization's external-facing services to an untrusted network, usually a larger network such as the Internet. Firewall can help to separate this network from your lan. wiki
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and untrusted external network, such as the Internet. Wiki