Ah, Here we go again.
YouTube loading is nothing more than just another name of YouTube CPM.
Some say, YouTube CPM, Some say, YouTube Loading.
But at the end of the day, It's just 2 names of 1 thing.
So, You can call it whatever you want but that doesn't change the fact that it's just another illegal, untethical and forbidden way of making money by watching and clicking on ads of your monetized YouTube channel.
You can call it "YouTube self clicking" too.
Just incase you still want to know about YouTube CPM then you can just tap here.