What is the primary function of a firewall in a network?

The primary function of a firewall in a network is to block unauthorized access while permitting outward communication. Firewalls create a barrier between a trusted internal network and untrusted external networks, enforcing a set of rules to control incoming and outgoing traffic. They are configured to allow legitimate traffic that meets certain security criteria while blocking unauthorized attempts to access network resources. This helps to protect sensitive data and the overall integrity of the network.

Other options describe functions that are either complementary or unrelated to the core function of a firewall. For instance, eliminating viruses and malware is typically the role of antivirus software rather than a firewall. Monitoring network traffic is a part of firewall functionality, but a firewall's primary purpose is to enforce access controls, rather than just monitoring. Providing data recovery services is entirely outside the scope of a firewall's functions, as it is more aligned with backup solutions and data management strategies. The focus of a firewall is centered on security and access management rather than these other aspects.