Surfactants (superficially active substances (SAS) is a group of substances that cause the reduction of the surface tension at the breaking point of phases of the substances that do not dissolve in each other.

Operational principle of SAS: If you wash your oily hands with water, you would not clean them, because water molecules don’t “stick” to the molecules of fat. So, to wash it off you need somehow to attach mud molecules to molecules of water. And here SAS ( soap in your case) makes a rescue performing the role of a bounding substance.

Classification of surfactants: ionic , cationic, nonionic, amphoteric.

Each type has its specific functions, advantages and disadvantages in application.