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

The primary function of a firewall in network security is to allow and restrict network traffic. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. By inspecting incoming and outgoing traffic based on predefined security rules, firewalls determine whether to permit or block that traffic. This capability is essential for establishing security perimeters and protecting network resources from unauthorized access or malicious activities.

While monitoring user activity can be part of a broader security strategy, it is not the primary role of a firewall. Similarly, encrypting data transmissions and detecting malware are functions carried out by different security tools. Encryption ensures that data remains confidential during transmission, and malware detection is associated with antivirus software or intrusion detection systems rather than firewalls.