Detergent
Detergents clean clothes using a similar method to soap. For liquid detergents, the molecules in detergent are inserted in water beforehand (that's why its liquid) so it doesn't clog the washer like powdered detergent. The molecules in both powdered and liquid detergent have one side that attracts to dirt, grime, oil, and other undesirable things on clothes. The other side attracts to water. When detergent is thoroughly mixed in with clothes, it detaches the dirt and grime and makes it soluble in water.  The used detergent is then rinsed out, normally piped into a sewer or septic tank. The washer then usually spins, to increase the g-force inside and effectively squeeze out the water. Afterwards, the wet (but clean) clothes are loaded into a dryer or hung out to air dry. When powdered detergent is used, the detergent is placed in water and mixed in with clothes very quickly, so there may be powder still on clothes because the detergent didn't have time to mix in with the water.