How does unity determine what constitutes a "Loaded" Scene.

My question is simple.
What is the function that unity uses to determine that a scene is loaded.

For example is the scene loaded when the awake method completes?
When the start method completes?
When a special rabbit jumps out of a hat somewhere in the back end and shouts “yo bro this biz is cooked”?

A little strange how this is not documented and no one has asked this.

I only ask because my async load is loading as if i called a normal load which is ridiculous.

maybe this could help

there is also

and to check the loading