| Class: A template for an object which contains variables and methods which can be inherited from other superclasses and whose calling sequence and existence can be defined by interfaces |
| Object or Instance: A particular realization of some class; different instances usually have different values for their variables or instances but the same methods |
| Simple types: variables defined by int, char etc. are NOT objects but each has an associated wrapper class which can be used with greater power but lower efficiency |
| Superclass: A class further up in the inheritance tree |
| Subclass: A class further down in the inheritance tree |
| Abstract classes:contain abstract methods which are not implemented and only define interfaces. Subclasses will provide implementations |