Question

I’m using this tutorial: http://www.objectdb.com/tutorial/jpa/eclipse/ee/ejb

I keep seeing words prefixed with @. Is there somewhere I can find a list of these and read about what they do?

Answer 1

These are known as annotations. Read the Java Tutorial article about them for an introduction. To quote that article:

Annotations provide data about a program that is not part of the program itself. They have no direct effect on the operation of the code they annotate.

Annotations have a number of uses, among them:

• Information for the compiler — Annotations can be used by the compiler
  to detect errors or suppress warnings.
• Compiler-time and deployment-time processing — Software tools can process annotation
  information to generate code, XML files, and so forth.
• Runtime processing — Some annotations are available to be examined at runtime.
  Annotations can be applied to a program’s declarations of classes,
  fields, methods, and other program elements.

After reading that article, you can move on to this reference of EJB annotations, which should explain the annotations featured in that particular tutorial.