Composition is a special kind of reusability. You don't extend an existing component, but you create a new, larger component by composing many smaller components together into a system of components.
In OOP languages, composition is often used to get around the multiple inheritance issues that most OOP languages have. Subclass polymorphism is always great until you reach the point where your design does not match the latest requirements in your project. Let's look at a simple example that illustrates this problem.
You have a Fisher class and a Developer class, both of which hold specific behaviors. Now, you'd want to create a FishingDeveloper class that inherits from both Fisher and Developer. Unless you're using a language ...
