Difference between Object and ObjectOcc

Hello Community,

although I have used Aris for a while, I am still a bit confused about the difference between Object and Object Occurence. As for my understanding, object is just an object. If the object occurs once in an model, then the object has occurence, which is the object in the model. Do I understand the difference in the right way?

I have also seen a function ObjDef() to acquire object definition from object occurence. Is there any function that works in the opposite direction, which means acquire ObjOcc from ObjDef? Function in both macro and report will be helpful.

Thanks in advance!