What is gray water and what are it's uses?

Question

What is gray water and what are it's uses?

Answer 1

The term gray water is used to describe water that has been used to wash things but is not from any toilet, the effluent form which is called black water.

Answer 2

"Gray water"  is defined as water that has been "used", but does not contain human waste (f***s or urine) or otehr poisons.  Like laundry water or diskwater.  It actually has no "use" -- it has already been used.

In order to prevent the dumping of garbage overboard, ships (navy vessels or cruise ships) will often store "gray water" and maybe even recycle it.

"Black water" contain human wastes (f***s or urine) or other poisonous products.  If "black water" contains ONLY human wastes it can often be recycled onboard.  If it contains other poisons, it might be stored until the ship returns to dock, when the "black water" is then pumped out and carried away for special processing.