Polyvinylpyrrolidone (PVP) gives products an extra fixative power: it forms a thin coating over the hair that helps to maintain it in the position you wish. It is also a binder, helping to control the viscosity of a product.
PVP (polyvinyl pyrrolidone) is a yellowish synthetic resin. It’s a polymer - a large molecule made of repeating units (monomers). These materials are of the same family of plastics but are not plastics themselves. It's a little like potatoes and tomatoes: they are perfectly edible whereas there is some deadly specimen belonging to the same nightshade family.
Polyvinyl pyrrolidone is water soluble, it does not naturally bioaccumulate in organisms like microbeads and instead pass through. It is also proved to be biodegradable in soils and water.