I am learning DAX and trying to understand Context transition and behaviour of Calculate. Conside the scenario where I am creating a calculated column and using a measure to create it.

Does DAX wrap the measure in CALCULATE automatically (which we can't see) ?  Or are we saying it behave as if it is wrapped inside CALCULATE but really it is not?  I also see statements that CALCULATE triggers context transiotion - which would means measures used in row-context are then wrapped in CALCULATE automatically.

Could you please help me understand.