Longevity: how long the scent remains detectable
Longevity is the length of time you can still smell the fragrance on skin or clothing. A scent may sit close to the skin later on and still be present.
Projection: how far the scent reaches
Projection describes how strongly a fragrance radiates around you at a given time. It is often strongest soon after application and then settles.
Sillage: the trail a fragrance leaves
Sillage is the scented trail noticed as you move through a space. A perfume can leave a noticeable trail without filling the room continuously.
Why performance changes from person to person
Temperature, spray count, application area, skin and clothing can all change how a fragrance behaves. One short test rarely tells the whole story.
A simple way to test performance
Use the same number of sprays in a normal day and check the scent after one hour, three hours and later instead of judging only the opening.
Strong projection in the first thirty minutes does not automatically mean long longevity, and a quieter drydown may still remain clearly detectable up close.