Introduction to Firewalls
Published: August 15, 2025
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet.
Firewalls can be hardware, software, or both. They are a first line of defense in network security, preventing unauthorized access while permitting outward communication. They work by analyzing data packets and determining whether they should be allowed through based on a set of rules.