What liquid is in the radiator? thank you

Coolant flows into the radiator core and air flows out of the radiator core. The hot coolant is cooled by radiating heat to the air, and the cold air is heated by absorbing heat emitted by the coolant, so the radiator is a heat exchanger. The radiator is filled with antifreeze, which is called antifreeze coolant. As can be seen from the name, it has two main functions: the first is to prevent freezing, and the second is to cool down. Antifreeze can prevent the vehicle cooling system from bursting when parking in cold winter, and prevent the radiator from being filled with cooling liquid in summer. It has the functions of anti-freezing, anti-radiation, anti-boiling, anti-scaling and protecting the hose. @20 19