A firewall acts as a barrier between trusted internal networks and untrusted external networks, filtering traffic to prevent unauthorized access, malicious activities, and data breaches.

It enforces security policies using techniques like packet filtering, stateful inspection, and application-layer analysis, and may also provide features such as network address translation (NAT) and VPN support. Firewalls come in various forms—including packet filtering, stateful, proxy, and next-generation firewalls—each offering different levels of protection and functionality.

In modern environments, platforms like Hedgehog can integrate firewall capabilities directly into the network fabric, enabling centralized management, automated policy enforcement, and advanced threat protection alongside regular network operations.

Firewalls are essential for maintaining network security, access control, regulatory compliance, and traffic monitoring in enterprise and cloud deployments.