Answer: An usable form of water can be defined as the water that can be used for the commercial purposes and drinking purposes.
The water that cannot be used for the commercial purposes and drinking purposes is known as unusable water.
Step-by-step explanation:
usable: Groundwater, freshwater lakes and rivers.
unusable: Glacier and ocean
The fresh water can be used for drinking purposes and the salty water is suitable for the drinking or commercial purposes.