[Mjulius513]

A firewall is a security tool that protects a network by controlling what traffic can go in or out. Firewalls protect networks by checking data packets and comparing them to security rules. One important feature is packet filtering, where the firewall looks at things like IP addresses and port numbers to decide if the traffic should be allowed. Another feature is stateful inspection, which means the firewall keeps track of active connections and only allows traffic that matches a safe, existing session. Some firewalls can also look deeper into the data at the application level, which helps block harmful content.

There are different types of firewalls. Packet-filtering firewalls are simple and fast. Stateful firewalls offer more protection by tracking connections. Application or proxy firewalls look at specific types of traffic, like web or email. Next-Generation Firewalls (NGFWs) combine all these features for stronger security. Firewalls are important for a security officer because they help stop attacks, enforce company security rules, and protect important systems from unauthorized access.