Why we use water in gas and diesel engine?

For cooling purpose we use water in Gas and Diesel engine. In every cycle there are firing occurred inside the Engine cylinder. as a result the Engine is going to be very hot and its cusses to fail the lubrication and other damages. So it should be controlled temperature of  Gas and Diesel Engine. Water circulation inside the Engine, Radiator and cooling Fan etc (cooling system) is used for temperature maintain in limited range.

For cooling purpose water circulate in head oil cooler turbo charger

For cooling purpose to maintain the temperature of Gas & Diesel Engine