What is the function of a firewall in a network?

A firewall serves the essential function of controlling network traffic to protect data integrity and security. Specifically, it acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. This involves monitoring incoming and outgoing traffic based on predetermined security rules. By allowing only authorized access while blocking unauthorized attempts, a firewall helps to prevent malicious attacks, data breaches, and other security threats.

It is crucial to distinguish this role from the functions of other options. For instance, boosting signal strength pertains more to hardware and networking equipment than to security protocols. Similarly, while firewalls play a role in network security, they do not store data securely; they primarily filter traffic instead. Lastly, firewalls do not replace antivirus software, as they focus on controlling access to the network rather than scanning for malicious software. Thus, the function of a firewall is clearly defined by its role in blocking unauthorized access while permitting outward communication, ensuring that internal systems remain protected from potential threats.