What is the typical use of a firewall?

A firewall is primarily designed to control incoming and outgoing network traffic based on predetermined security rules. This is essential for protecting private networks from unauthorized access and attacks while allowing legitimate communication to flow. By doing so, it establishes a barrier between a trusted internal network and untrusted external networks, such as the internet. Firewalls can be hardware-based, software-based, or a combination of both, and their configurations can be tailored to meet specific security requirements.

The other options, while related to different aspects of IT and network management, do not align with the core functionality of a firewall. Storing files securely relates more to file storage solutions and security protocols rather than traffic management. Creating virtual machines pertains to virtualization technologies rather than network traffic control. Monitoring network usage involves analyzing traffic patterns and performance but does not inherently control or regulate that traffic, which is the primary role of a firewall.