This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
An EJB is a special class that works with an application server container. The container knows how to inject resources and add wrappers for security/transactions. An EJB is identified with an annotation or in an XML file so the container knows it is special.