Some classes are fundamentally different from others in the way they should be instantiated. Most classes define a template for a collection of properties and behaviors that might be instantiated many times in a scene as
GameObjects. An enemy class can be used to instantiate many enemy objects, a power-up class for many power-up objects, and so on. However, some classes such as
SaveGameManager are intended to exist as a lone entity, one that consolidates a unified set of behaviors. In short, there should only ever be one instance of the class at any one time and never more than one. To have more than one instance would either be nonsensical or damage the ...