A surfactant is a substance that decreases the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. Surfactants are usually organic compounds that are amphiphilic, meaning that each molecule contains a hydrophilic "water-seeking" group (the head) and a hydrophobic "water-avoiding" group (the tail) . As a result, a surfactant contains both a water-soluble component and a water-insoluble component. Surfactants may function as emulsifiers, wetting agents, detergents, foaming agents, or dispersants. They play an important role as cleaning, wetting, dispersing, emulsifying, foaming, and anti-foaming agents in many practical applications and products, including detergents, fabric softeners, motor oils, emulsions, soaps, paints, adhesives, inks, anti-fogs, ski waxes, snowboard wax, deinking of recycled papers, in flotation, washing and enzymatic processes, and laxatives. Surfactants work by adsorbing onto the surfaces or interfaces of a system and altering the surface or interfacial free energies of those surfaces. When there are a sufficient amount of surfactant molecules present in a solution, they combine together to form structures called micelles. The surfactant heads position themselves so they are exposed to water, while the tails are grouped together in the center of the structure protected from water. Surfactants are a primary component of cleaning detergents, and they stir up activity on the surface you are cleaning to help trap dirt and remove it from the surface.