Unscented vs Fragrance Free

Generally speaking, if a product is made with scented ingredients, and additional ingredients are added to neutralize that aroma, you end up with an unscented product which is marketed as such. It still contains the fragrance chemicals, though neutralized. 

The chemicals used to neutralize fragrance in skin care products can be harmful. 

If an item is fragrance-free, then it is made with ingredients whose primary purpose is not to impart a scent, but to provide other characteristics to the final product. In other words, nothing is added to specifically to add a fragrance. The end result is that sometimes these have a scent and there is no attempt to cover up or neutralize it. 

The bottom line is that there is no guarantee a product will be completely odour free.