Why do detergents remain effective for washing clothes whereas with soaps foam is formed with difficulty?

Explanation

Detergents are also known as soapless soaps as they are chemically not soaps but bring about the same type of cleansing action that soaps do. Detergents are generally ammonium or sulphonate salts of long-chain carboxylic acids. The charged ends of these compounds do not form insoluble precipitates with the calcium and magnesium ions in hard water.
Thus, they are effective in hard water. Soaps mixed with hard water containing calcium and magnesium salts react with these salts and form an insoluble scum.