Hydrosols or floral waters are a by-product of the distillation of essential oils. They offer a gorgeous but very fleeting fragrance experience.
They are a lovely alternative to spray perfume and Eau de Cologne. Many people who are allergic or bothered by perfumes find that they don't have a problem with hydrosols.
I use hydrosols as facial sprays in my rituals sometimes. They offer a beautiful and potent experience.