Soap is a product made from fats and oils and brought into chemical contact with alkalis. It gently cleans by lowering the surface tension of water and by emulsifying oils and fats so they can be rinsed away.

Soil particles and molecules on the surface to be cleaned are attracted to each other by their opposite electrical charges. When water molecules come in contact with both sets of particles, they form electrical layers between the soil and surface to be cleaned. The water molecules join with the soil and surface particles, forming a new molecular structure which actually repels each other, thereby removing soil. In addition, water may cause the surface to hydrate and swell, creating a physical distance between the soil particles and surface molecules.

The need for scrubbing is reduced by adding a surfactant (soap). When the soap bonds with the surface to be cleaned, it takes the place of the existing bond with the soil molecule and separates the soil from the surface.

Soap operas were named as such because of the number of soap/detergent advertisements that were televised and watched by American housewives during the day.