What is the role of a firewall in network security?

The role of a firewall in network security is primarily to monitor and control incoming and outgoing network traffic. Firewalls act as a barrier between trusted internal networks and untrusted external networks, such as the internet. They use predetermined security rules to determine which traffic is allowed or denied, effectively filtering traffic to prevent unauthorized access and attacks.

By analyzing data packets at various layers of the network stack, firewalls help prevent incidents such as unauthorized access attempts, malware infiltration, and data exfiltration. This capability makes them a fundamental component of a network security architecture, ensuring that only legitimate traffic is permitted while blocking potentially harmful communications.

While other options touch on important aspects of network security, such as data encryption, backup processes, and vulnerability assessments, they do not capture the primary function of a firewall, which is focused specifically on traffic control and monitoring.