The Java2 version is best for documenting collections of loosely related classes called packages. You should always make the documentation available on any class you publish so that others can use it. You should have noticed that my favorite technique for Applets is to add links to a published test page that links to the source code and to the documentation. Follow the links to the code and then to the documentation, and from there to the documentation on String. You won't get far with Java without understanding polymorphism .
Objects know who they are and automatically behave in character.
When a variable refers to an object then all operations applied to that variable automatically are taken form that objects class. You may want to add a note and link on polymorphism to your lab notes. You can assemble these into complicated interface. There is a rather clever scheme that lets Java layout the components of a graphic for you. This means you don't have to work out the precise positions of buttons and menus on the screen.