Terminology: Inline IDS, IPS and Application Layer Firewall

Hi,
I wonder if there are any conceptual differences between:
- inline IDSs,
- IPS and
- Application Layer Firewalls

Or are this just three terms that mean the same?
To my understanding all three concepts do access control up to the application layer and in addition, they all have a certain impact on the network performance as all packets are routed through them.

Regards
Andreas



------------------------------------------------------------------------
Test Your IDS

Is your IDS deployed correctly?
Find out quickly and easily by testing it with real-world attacks from CORE IMPACT.
Go to http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708 to learn more.
------------------------------------------------------------------------