[Carlos Martes]

Firewalls are one of the most important tools because they control what traffic is allowed in or out of a network. One characteristic of a firewall is traffic filtering, where it checks packets based on rules such as IP address, port number or protocol. Another characteristic is stateful inspection, meaning the firewall tracks active connections and only allows traffic that matches an approved session. A third type is the application layer firewall, which can inspect traffic at a deeper level such as blocking suspicious web request or malware. From the text and videos, the main idea is that firewalls act as a barrier between trusted and untrusted networks. An additional reference often highlights how modern firewalls also include intrusion prevention and logging features. Firewalls are important for a security officer because they reduce threats, help enforce company policies, and provide alerts when something unusual happens. Without them, networks would be exposed to constant attacks.