What function does a firewall perform in a network?

A firewall serves a critical function in a network by monitoring and controlling the incoming and outgoing traffic based on predetermined security rules. It acts as a barrier between trusted and untrusted networks, allowing or blocking data packets according to security policies. This proactive measure helps prevent unauthorized access, attacks, and data breaches by filtering out malicious traffic and enabling only legitimate communications.

While encryption of sensitive data is essential for protecting data confidentiality, and multi-factor authentication enhances security by requiring multiple verification methods, these functions are not performed by firewalls. An intrusion detection system, on the other hand, typically focuses on identifying potential security breaches or anomalies in network traffic rather than actively controlling access like a firewall does. Thus, the role of a firewall is distinct and focused on traffic management and security enforcement.