How do firewalls contribute to network security?

Firewalls are a critical component of network security as they monitor and control the incoming and outgoing traffic based on a set of predetermined security rules. This capability allows them to act as a barrier between a trusted internal network and untrusted external networks, such as the internet. By filtering traffic and enforcing security policies, firewalls can block unauthorized access, prevent various types of attacks, and reduce the risk of data breaches.

When a firewall is properly configured, it can allow or deny traffic based on a variety of criteria such as IP addresses, protocols, and port numbers. This selective control enhances the overall security posture of the network by ensuring that only legitimate traffic is permitted while harmful or suspicious activity is blocked. This proactive approach to managing traffic helps organizations safeguard sensitive information and maintain regulatory compliance.

When considering the other options, encrypting all data transmitted is a different security mechanism that serves its own purpose but does not inherently relate to the role of a firewall. Providing antivirus protection pertains to malware detection and removal, which is outside the primary function of a firewall. Allowing unlimited internet access directly contradicts the firewall's purpose, as it would lead to uncontrolled traffic that could compromise security. Therefore, controlling incoming and outgoing network traffic based on predetermined security rules accurately describes the essential