Imagine building a car with modern software development.  This is a wheel.  It spins.  We use wheel components for the steering wheel, because it is round.  We compile the seat components with the wheel framework.  The car is made up of 3,000 wheel frameworks.  Oh my, the car is heavy.  For new cars, rather than use the original car components, we put the entire car into a service you can use on the web, and then encapsulate an entire car into each component.