what is the diffence between WAS and IIS?

Question

Is WAS distinct from IIS? How is WAS better than IIS?

Answer 1

Windows Process Activation Service, also referred to as WPAS, is a new component in IIS 7.0 that manages application pool configuration and worker processes instead of the WWW process. This enables the same configuration for both HTTP and non-HTTP sites to be used.

http://searchwindowsserver.techtarget.com/tip/Windows-Process-Activation-Service-in-IIS-70