You can't always remove stains from dirty objects by washing them with water. It is often necessary to add to this water a special product that penetrates the stains and makes them disappear: it is the detergent.
The most common detergents are soaps, whose essential property is to break up insoluble grease stains into tiny particles, which disperse in the water: soaps emulsify grease. Modern detergents include a number of petroleum by-products in the form of white granules, sometimes perfumed and usually impregnated with a fluorescent product that gives dry linen a special shine. Detergents should not be confused with solvents used in dry cleaning.
