What is the purpose of a firewall in computer security?

The purpose of a firewall in computer security is to scan incoming data for security compliance, which aligns with the functionality presented in the chosen answer. Firewalls act as a barrier between a trusted internal network and untrusted external networks. They monitor and control incoming and outgoing network traffic based on predetermined security rules, allowing only legitimate data to pass through while blocking potentially harmful data packets that could lead to unauthorized access or attacks.

By analyzing traffic, firewalls help ensure that incoming data complies with the organization's security policies. This can prevent various cyber threats, such as malware, hacking attempts, and denial-of-service attacks, thus maintaining the integrity and confidentiality of the network and its resources.

In contrast, other options do not accurately reflect the role of a firewall. Storing information pertains more to data storage solutions rather than security mechanisms. Designing programming software is focused on development tools rather than security infrastructure, and enhancing screen resolution relates to visual display aspects rather than network security. Hence, the correct understanding emphasizes the firewall's core function of analyzing and controlling data traffic for security purposes.