What is a firewall’s primary function?

The primary function of a firewall is to act as a barrier between trusted and untrusted networks. Firewalls are critical components in network security, designed to monitor and control incoming and outgoing network traffic based on predetermined security rules. By doing so, they effectively protect internal networks from unauthorized access and potential threats originating from external sources. This function is essential for maintaining the integrity, confidentiality, and availability of data within a secured environment.

In contrast, the other options describe functions that are not associated with firewalls. Speeding up data transmission is more aligned with network optimization techniques rather than security. Managing user permissions pertains to access control within systems or applications, which is typically handled through user management systems rather than firewalls. Creating backups of important files relates to data management and recovery strategies, which are separate from the security functions provided by a firewall. Thus, the role of a firewall is specifically centered on security through segmentation of traffic between different types of networks.