What is a firewall's primary function in network security?

A firewall's primary function in network security is to monitor and control incoming and outgoing network traffic based on predetermined security rules. This role is essential for protecting a network from unauthorized access, attacks, and various security threats.

When a firewall is deployed in a network, it establishes a barrier between a trusted internal network and untrusted external networks, such as the internet. By analyzing data packets and applying the set rules, firewalls can allow or block traffic depending on whether it meets the specified criteria. This capability helps organizations safeguard sensitive information, prevent security breaches, and maintain overall network integrity.

Other choices relate to different aspects of network and data security but do not accurately describe a firewall's primary purpose. For instance, while encryption of sensitive data is crucial for data protection, it is not something that firewalls do directly. Similarly, creating backups and installing software updates are important maintenance tasks for IT systems but are carried out by different types of tools and processes, not firewalls.