For EJBs (Enterprise Java Beans), the purpose is also "to build reusable
components", and hence the same terminlogy "Beans" is used. (A bean, which
you just drop somewhere and then use it).

However, other than that, they are totally different things. EJBs are used
to write server-side software (more precisely, the back-end), and to that
extent there is a whole framework for threading, security and all that
around it. (Free PDF book on EJBs:
http://www.theserverside.com/books/wiley/masteringEJB/)

 David.