What is a network firewall?

Network firewalls are security devices or software designed to monitor and control incoming and outgoing network traffic based on predetermined security rules. They act as a barrier between a trusted internal network and untrusted external networks, such as the internet, to prevent unauthorized access and threats. Firewalls can be hardware-based, software-based, or a combination of both, and are essential components of modern cybersecurity strategies. They help protect sensitive data, maintain privacy, and ensure compliance with security policies.