a difference between Watercolor, Oils, and Acrylic? What a silly question you ask. Well yes, there is...it is the medium itself. When you paint in watercolors, you are using a pigment that is mixed with a substance called gum arabic, which is the binder. The gum arabic comes from the Arabic tree so it is a natural component. There are other common additives, like glycerin, humectant, extender, dispersant, and water. Some use more additives, like two or more pigments and also maybe a brightener.
In Acrylic paint you also start with pigment and
a synthetic resin binder, The acrylic also has additives of Surfactants, to disperse the pigment, anti-foaming agents to stop the paint from frothing. Cheaper paints also contain things that are cheaper than the pigment, like dyes, opacifiers, and fillers. Acrylic paint also has lots of mediums for various things like thickening the paint, keeping it wetter when painting in Plein air....and lots more, too many to list.