Autocad Drawings Standard Size Question

Gud Eve ! everyone.. im just wondering if ur using a standard size, inches or scaling limitations depends in an exterior
where u created.? i dont know if my info are right when we create an exterior its gonna be a real size or inches of a real house.? haha! or it depends
in the zoom of the camera.? im not study autocad but i wanna learn dats y i wanna ask dat thing.?

if we knew' when we edited some others exterior max files its gonna be too much for our scene or too small
unlikeness hard to get in.? wanna know if ders a standard rule for creations of interior or exterior.??