What is the function of a firewall in network security?

The function of a firewall in network security is to monitor and control network traffic. Firewalls act as a barrier between a trusted internal network and untrusted external networks, such as the internet. They analyze incoming and outgoing traffic based on predetermined security rules and policies. By doing so, firewalls can effectively block malicious traffic attempts, unauthorized access, or any other potentially harmful activities while allowing legitimate communication to pass through.

Firewalls achieve this through various methods, such as packet filtering, stateful inspection, or proxy services. They can be hardware-based, software-based, or a combination of both. The primary goal is to establish a secure network environment by preventing unauthorized users or malicious attacks from penetrating the network infrastructure.

Other functions mentioned, like storing encrypted files, providing internet access, or backing up data, do not pertain to the core purpose of a firewall. Instead, these tasks are handled by other security measures or systems designed explicitly for data storage, internet routing, or data backup solutions.