Coolant is the generally accepted term for the liquid that absorbs heat from the engine and releases it through the radiator.
As the coolant circulates through the system, it transfers heat to the radiator and into the air. The liquid is cooled, fed back to the engine through the cooling system. and the cycle repeats. The average motors should consider changing their coolant every two years, or 24 thousand miles. However in specific cases, motorists should refer to the owners manual for further guidance.