While both eau de toilette and eau fraiche are types of fragrance concentrations, they differ in their composition and longevity. Eau de toilette typically has a higher concentration of essential oils compared to eau fraiche, resulting in a longer-lasting scent. On the other hand, eau fraiche has a lower concentration of essential oils, making it lighter and more suitable for daytime wear or hot weather conditions. It provides a refreshing and invigorating aroma without being overpowering.