These are produced during the distillation process. When the oil is removed the water which is left contains small quantities of the more water soluable elements of the essential oil. These are known as hydrosols, hydrolats or floral waters.
They are very gentle and safe to use neat. Lavender Hydrolat is particularly helpful for eczema skin.
Floral waters often consist of water with essential oil added to it. Shirley Price hydrolats are true fresh season essential waters.
Hydrolats make an excellent skin toner or additions to creams and lotions.