This idea is known as a ‘model’. If we don’t abstract we may end up with the wrong solution to the problem we are trying to solve. With our cat example, if we didn’t abstract we might ...

Today's applications are often programmed in multiple layers of abstraction. For example, a program can be written by selecting menu options and dragging icons around the screen. These movements ...

The problem could first be decomposed into modules, each of which would be a particular shape, for example rectangle, square and triangle. Abstraction can then be followed for each module.

Interfaces, however, support multiple inheritances where abstract classes don't. Implementation is done similarly in Java. For example, using the keyword implements will make a Java interface, while ...