# What are the roles of pre-heating and re-heating in inflation?

During inflation, the universe is thought to have cooled by a "factor of 100,000 or so"

The abstract of this paper mentions 'preheating' as playing a role in particle production. Is this 'preheating' referring to inflation?

Because I am trying to communicate this to a non-science audience, I need to use analogies. I previously understood it as reheating 'cooking' the first particles... however, the above seems to suggest that supercooling 'condensed' the first particles, which seems to make more sense. Which of these two analogies is more correct?

During inflation you have the inflaton field which stays almost constant in a flat region of its potential and therefore drives the exponential expansion of the universe. Because the universe expands by a huge amount during inflation ($\sim e^{60}$) the energy density of any particles that there might have been is diluted and therefore, for all intents and purposes, at the end of inflation the universe is empty of any particles and is only filled with the inflaton field (and possibly with other light scalar fields).