Exactly...
It's not clear cut, and different people will mean different things, but generally an Enhancement in my opinion is a single stage machine polish, which depending on paint hardness, can remove maybe 50-80% of defects and generally is done in the space of a day.
A correction detail takes this further, by being a multistaged machine polish, where generally a heavier compound is used initially to remove deeper defects such as scratches, but this process itself leaves its own marking behind, so is refined with one or two more polishing stages, to ensure the finish is as level and crisp as possible, within budget and time allowed.
Most people would be very happy with results from an enhancement, but if striving for perfection, then a 2-3 day correction detail is generally required, to remove every last defect. Also, detailing isn't just about machine polishing, for a 2-3 day job, I'd expect to see the wheels being removed to be cleaned and sealed properly, arches cleaned properly and dressed, engine bay... etcetc, not all of this is possible in the space of a day - not being done properly, anyway.
Most of what I get asked to do, is to just concentrate on machine polishing (so rarely do I do an interior for example) as that's the most challenging and skillful part of 'detailing' and do what I can in the space of a day.
