Division into parts takes a complex system, and divides into into component
parts, which can then be considered in isolation.
Characterized by sentences that have the words ``has-a''
Allows us to drop down a level of complexity when we consider the
component in isolation.
- A car has-a engine, and has-a transmission
- A bicycle has-a wheel
- A window has-a menu bar
Intro OOP, Chapter 2, Slide 15