EJB vs JSP+Servlet+beans, cloudy

[Tom Niedoba]

Hello, I'm kinda new to web development but I've used JSPs, servlets and even beans (session, application...). What I'm unclear about is what exactly EJB is.
An application I write using jsp, servlets, and beans running on tomcat is not an EJB app or is it? What makes an application an EJB application? Looking at code of an existing app (I got one at work nobody knows anything about as it came with the purchase of another business) how can I tell if it conforms to EJB and requires more than tomcat to run... like JBOSS? Can I take an app that has no instructions about it and figure out how to set it up and run it? I got apache/tomcat setup, not sure what to do with this though!
Any help appreciated.
Tom

[Rufus BugleWeed]

JavaBeans and EJBs are both component models. JavaBeans are classes which follow a convention. EJBs also follow a convention but its more defined in that classes must implement interfaces or extend other classes.
This link is a little bit dated but enough to get you started.