Linked from
The 13 pages that link to Detergent, each with the reason it gives.
ZeoliteRelated: Zeolite builders can soften wash water by binding calcium and magnesium ions.
MicelleRelated: Detergent micelles can enclose oily material and carry it into the wash water.
Sulfur trioxideRelated: Industrial sulfonation using SO₃ makes surfactants used in many detergents.
Washing machineRelated: It loosens and suspends soils so wash water can carry them away.