What does a firewall primarily do?

A firewall primarily functions as a security system that protects networks from unauthorized access. It acts as a barrier between your trusted internal network and untrusted external networks, such as the internet. By monitoring and controlling incoming and outgoing network traffic based on predetermined security rules, a firewall helps to prevent potential cyber threats like hacking, data breaches, and malware attacks.

This protective capability is essential for maintaining the integrity, confidentiality, and availability of data within a network. Firewalls can be either hardware-based, software-based, or a combination of both, and they provide a critical layer of defense in network security strategies.

The other options mention aspects that are unrelated to the primary function of a firewall. For instance, enhancing internet speed, repairing damaged files, and optimizing data storage pertain to different areas of technology and do not relate directly to the primary role of a firewall in safeguarding network integrity.