What is Graywater
Greywater is all wastewater that is generated in household or office building sources without fecal contamination. Therefore, by definition, greywater does not include the discharge of toilets or highly fecally contaminated wastewater, which is designated sewage or blackwater and contains human waste.
Any water that has been used in the home, except water from toilets, is called Greywater. Dish, shower, sink, and laundry water comprise 50-80% of residential "waste" water.
This may be reused for other purposes, especially landscape irrigation.