| A | B |
|---|
| Class | a class contains a list of fields (at tributes) that describe objects in the real world. A class also defines the behavior of an object through methods. |
| Instance | an instance (object) is created from a class and describes a particular thing in the real world. |
| Object | they have methods. Invoking a method performs an action. The behavior of each objects have the same fields and methods. Many different objects can be created from the class; all of these objects have the fields and methods. |
| Return type | tells us what information the method will give us. |
| Void return | it means that the method will not give us an information. |
| Boolain return | type can only returnt he values true or false. |
| Description | in each method, shown in the object menu, including the return type, method name, and parameter list, is called the method signature. |
| Subclass | A class that represents a specialization of another. In Greenfoot, this is-a is whonw with an arrow tot he super class. |
| Behavior | a class that is defined by its source code. |
| Source code | must be compiled or translated into machine code before it can be executed. |
