What exactly does "heat training" mean?

[nebulanorton]

I hear this term thrown around a lot, but I am still not quite sure what people mean. What it has always implied to me is that the hair is damaged enough from heat that it won't really go all the way back to its naturally curly state.

Is that what they mean?

 

[Keen]

Here you go

WHAT EXACTLY IS HEAT TRAINING AND HOW DOES IT DIFFER FROM HEAT DAMAGE!