- Purpose: Acts as a barrier between trusted internal networks and untrusted external networks, filtering incoming and outgoing traffic based on predefined security rules.
- Types:
- Packet-Filtering Firewalls: Inspect packets at the network layer and filter based on IP addresses, ports, and protocols.
- Stateful Inspection Firewalls: Monitor active connections and make decisions based on the context of the traffic.
- Next-Generation Firewalls (NGFWs): Combine traditional firewall capabilities with advanced features like intrusion prevention and application awareness.