server « Container « JSP-Servlet Q&A

1. Difference between an application server and a servlet container?

I am trying to understand the difference between a full fledged application server(e.g. Weblogic, JBoss etc.) and a servlet container(Tomcat, Jetty etc.) How do they differ and when to use which? Thanks,

2. What Web Server/Servlet Container Do You Use For Clojure Web Apps?

Possible Duplicate:
Good Web Server/Servlet Container for Clojure Web Apps?
I'm looking around to decide what web server to use for my clojure web app and ...