Difference between Firewall and IDS

Feature	Firewall	Intrusion Detection System (IDS)
Purpose	Blocks/filters unauthorized traffic	Detects suspicious/malicious activity
Action	Prevents intrusion	Detects and alerts about intrusion
Traffic Control	Yes	No
Placement	Usually at the network boundary	Can be placed inside the network
Types	Packet-filtering, stateful, proxy, NGFW	Signature-based, anomaly-based, hybrid
Real-time Response	Can block traffic	Generally passive (alerts only)
Focus	Known threats and access rules	Unknown or suspicious behavior patterns

Summary

• Firewalls act as gatekeepers, blocking or allowing traffic.

• IDS acts as a watchdog, monitoring for unusual or malicious activity.

• Both are essential for a layered security architecture.