While it’s true that “parfum” or “parfume” is simply French for “perfume,” the way the fragrance industry utilizes the word causes some confusion. The key lies in whether a particular scent is classed as “eau de parfum” or as pure “parfum.”

What’s in a Name?

To avoid confusion, parfum—the most expensive and the strongest kind of scent–can also be referred to as extrait, or “pure perfume,” while the next highest-concentration of scent is known as “eau de parfum.”

Specific Ratios

To be classified as eau de parfum, the scent must contain at least 8 to 15 percent of fragrance or essential oils. Perfume’s strength comes from a percentage of scent elements of between 15 and 30. The average concentration is 15 percent for eau de parfum and 20 percent for perfume.

Lasting Impressions

How long a scent stays on the skin is usually referred to as “tenacity.” Perfume’s tenacity ranges up to eight hours, while parfum lingers no more than six hours.

Effect of Price

Not surprisingly, the more intensely a perfume alcohol is dosed, the higher the price. Chanel sells its classic “No. 5” perfume for $260 an ounce, while the eau de parfum spray goes for a relative bargain–$80 for a 1.7 oz. bottle.

Concentration Range

From weakest to strongest, scent categories range from eau fraiche, eau de cologne, eau de toilette, eau de parfum and perfume.