Soaps and detergents
Sodium and pottasium salts of fatty acids such as palmitic acid, stearic acid, oleic acid etc are called soaps, while detergents are ammonium or sulphonate or sulphate salts of long chain hydrocarbons containing 12-18 carbon atoms.
Advantages of detergents over soaps for washing purposes:
Synthetic detergents can be used in hard water whereas some of the soap gets wasted if the water is hard.