How does a firewall improve computer security?

• A. By deleting harmful files
• B. By updating software regularly
• C. By monitoring and controlling network traffic
• D. By optimizing performance

Answer: (C)

A firewall improves computer security primarily by monitoring and controlling network traffic. It acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. By analyzing incoming and outgoing traffic, the firewall can block or allow data packets based on predefined security rules. This helps prevent unauthorized access and potential threats from reaching the computer or network.

In contrast, deleting harmful files pertains to antivirus software, which actively scans for and removes malware. Updating software regularly is crucial for maintaining security, as it ensures that software has the latest security patches, but this is not the primary function of a firewall. Optimizing performance relates to improving the speed and efficiency of computing resources, which is unrelated to the security functions of a firewall. Thus, monitoring and controlling network traffic is the key role that illustrates how a firewall enhances security.