What is the primary function of a firewall in network security?

The primary function of a firewall in network security is to monitor and control incoming and outgoing network traffic based on predetermined security rules. This means that firewalls act as a barrier between a trusted internal network and untrusted external networks, such as the internet. By analyzing packets of data, firewalls determine whether to allow or block specific traffic based on established security policies. This capability is critical for protecting sensitive information and systems from unauthorized access, attacks, and other security threats.

Firewalls can be configured to allow certain types of traffic, such as web browsing or email, while blocking other types, such as malicious data packets or unauthorized access attempts. Additionally, firewalls can help to prevent data loss and enforce compliance with security regulations.

The other options describe functions that can be associated with network security in broader contexts but do not specifically embody the primary role of a firewall. For instance, while encryption is a vital aspect of securing data, it is not a primary function of a firewall. Blocking all incoming traffic is overly restrictive and not a practical approach, as it would prevent legitimate communications necessary for network operation. Similarly, while providing VPN services enhances security by creating secure connections over the internet, this is not the main focus of a firewall. Instead, a firewall's essential