The GameObject

The GameObject is, in many senses, the fundamental unit or entity inside a scene. It corresponds most naturally to what we'd call a thing in the everyday sense. It doesn't really matter what kind of context-specific behaviors or things you'll actually need inside your own games, because in all cases, you'll need GameObjects to implement them. GameObjects don't need to be visible to the gamer; they can be, and often are, invisible. Sounds, colliders, and manager classes are some examples of invisible GameObjects. On the other hand, many GameObjects will be visible: meshes, animated meshes, sprites, and so on. In all cases, however, whether visible or invisible, the GameObject is instantiated inside a scene as a collection of related components. A component is essentially a class derived from MonoBehaviour, and it can be attached to a GameObject in the scene to change its behavior. Every GameObject has at least one minimal component in common, and it's impossible to remove it...