小写的object是泛类, 引用的是System.Object.

大写的Object引用的是UnityEngine.Object.

UnityEngine.Object继承System.Object.

需要注意的是重载的运算符.

System.Object a = new System.Object();

UnityEngine.Object b = new UnityEngine.Object();

Debug.Log (a);　　//System.Object

Debug.Log (b);　　//null