While the terms “fragrance” and “perfume” are often used interchangeably, they are not the same. The fragrance is the broadest term that refers to any scent. Perfume refers to a higher oil concentration that makes the scent last longer, often around 20 - 30% concentration. Eau de Toilette is a lighter fragrance with a lower concentration, usually between 5 - 15%. Cologne has the lowest concentration of oils, at around 2 - 4%. As a result, it’s a lighter scent that doesn’t last as long.