For example, I have a scene. The scene has a GameObject. The GameObject has reference to a prefab, like this:
class MyGameObject : MonoBehaviour
[SerializedField] private GameObject myPrefab;
And I assign a prefab to it in the inspector.
The prefab has references to some really huge resources, e.g. a MeshFilter with a hi-res mesh.
Now my question is: when is the mesh loaded? When I load the scene? Or when I instantiate the prefab for the first time? Also, is there a "resource loading debugger" where I can find out the answers myself?