Surfactant

Surfactant is short for surface active agent, which describes any chemical which changes the surface of a liquid when added to it.

Soap is a common surfactant in that it reduces the surface tension of water, allowing it to penetrate soil more readily. Modern synthetic detergents act in the same manner, allowing the solution to wet the surface quickly and loosen the soil.

In the home, surfactants are found in hard surface cleaners, cleansers, and dishwasher detergents.

Reference:    

American Cleaning Institute