Which is a primary function of personal firewalls?

The primary function of personal firewalls is to protect a single computer from unwanted Internet traffic. Personal firewalls act as a barrier between a computer and the internet, monitoring and controlling incoming and outgoing traffic based on predetermined security rules. They help block unauthorized access to the system and prevent harmful traffic, such as malware attempts or intrusion attempts, from reaching the computer. By doing so, they enhance the security of individual devices, making them less vulnerable to external threats.

In contrast, monitoring network traffic across multiple computers typically falls under the capability of network firewalls rather than personal firewalls. Removing malware is a function handled by antivirus and anti-malware software, while encrypting outgoing web traffic is the role of encryption tools and protocols, such as VPNs or HTTPS, not personal firewalls. Therefore, the focus of personal firewalls on a single device's protection from internet threats makes the identification of their primary function clear.