What is a firewall?

A firewall is fundamentally a network security device designed to monitor and control incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted internal network and untrusted external networks, such as the internet, ensuring that malicious traffic and unauthorized access attempts are blocked. By filtering data packets, a firewall helps prevent attackers from gaining access to sensitive information or systems within the network.

The role of a firewall is critical in maintaining network integrity, protecting against various cyber threats, and enforcing security policies. Unlike malware detection software, which identifies and removes harmful software, a firewall focuses on traffic control. Additionally, it is distinct from tools like password managers that store and manage user credentials, or data backup methods, which are designed to preserve data rather than manage network traffic. This clarity on what a firewall does helps reinforce its importance as a frontline defense mechanism in network security.