Lavandula Angustifolia Flower Water
In general, flower waters are diluted versions of essential oils meaning they contain pretty much the same components but in much-reduced concentrations. So lavender flower water is a highly diluted version of lavender essential oil. According to manufacturer claims, it's traditionally used as bath water or wash water and might be useful for acne-prone or oily skin thanks to lavender's antibacterial properties.
We wrote in detail about lavender essential oil and why we prefer it not to have in skincare products (in short, it not only contains fragrant components but research shows it might be cytotoxic even at low concentrations) so we would also be cautious with the lavender water. It's much more diluted - so less effect and less side effect - but why risk it?