Parfum: 20-30% fragrance oil, highest concentration, most potent and long-lasting. Eau de Parfum (EDP): 15-20% oil, longer-lasting and intense. Eau de Toilette (EDT): 5-15% oil, balanced longevity and projection. Eau de Cologne (EDC): 2-4% oil, lighter scent. Eau Fraiche: Similar to EDC but contains a lower concentration of fragrance oils. These variations indicate the perfume's strength and lasting power.