What is the primary function of a firewall?

The primary function of a firewall is to filter network traffic based on security rules. This involves analyzing incoming and outgoing data packets to determine whether they should be allowed or blocked based on predefined security criteria. By establishing these rules, firewalls help protect networks from unauthorized access, harmful attacks, and other security threats.

For instance, a firewall can efficiently ensure that only legitimate traffic reaches sensitive internal systems, thereby enforcing security policies and maintaining the integrity of the network. This filtering process is essential for preventing malware, intrusions, and other forms of cyber threats from infiltrating a network.