Which type of software is designed to monitor and control network traffic according to defined security settings?

A firewall is specifically designed to monitor and control network traffic based on predefined security rules. It serves as a barrier between trusted internal networks and untrusted external networks, such as the internet. By implementing security settings, firewalls can allow or block data packets based on criteria such as IP addresses, port numbers, and protocols. This functionality is essential for protecting systems from unauthorized access, attacks, and breaches, ensuring that only legitimate traffic is permitted.

In contrast, antivirus software primarily focuses on detecting and removing malicious software on individual devices rather than managing network traffic at a larger scale. Routers are responsible for directing data packets between different networks but do not inherently enforce security policies on that traffic. Proxy servers act as intermediaries between clients and internet services, which can provide some level of anonymity or content filtering, but they do not have the security monitoring capabilities that firewalls possess. Therefore, a firewall is the most appropriate choice for controlling network traffic based on security settings.