A fragrance is classified into different types based on the strength of the alcohol and / or water it carries with the fragrance oils. The type is always mentioned on the bottle. Typically the stronger the fragrance oil content, the longer is lasts. For any given brand of fragrance, the price goes up as the concentration goes up.
Perfume Extrait: This is the most concentrated form of fragrance available that one can buy. It carries 15-40% of perfume oil dissolved in alcohol.
Eau de Parfum (EDP) : This carries 10-20% of perfume oil. Usually lasts up to 6 hours
Eau de Toilette (EDT) : Carries 5-15% of perfume oil. Lasts between 4 to 6 hours.
Eau de Cologne(EDC): This carries 3-8% of perfume oil. This lasts up to 4 hours.
Deodorant / Antiperspirant : Carries 1-3% of fragrance oils but is dissolved in water and not alcohol.