Solvent
Although water is an excellent solvent, it cannot dissolve everything. Non-polar substances like oils and fats do not dissolve well in water because they do not form hydrogen bonds and are not attracted to polar water molecules. A common saying in chemistry is “like dissolves like,” meaning polar substances dissolve well in polar solvents, and non-polar substances dissolve well in non-polar solvents. Non-polar solvents usually do not mix well with water, which is where the expression "oil and water don't mix" comes from.