Antifreeze is a liquid used in vehicles to lower the freezing point of the coolant in the engine. It helps prevent the engine from freezing in cold temperatures and protects it from overheating in warmer conditions. Antifreeze is typically made from ethylene glycol or propylene glycol, which are effective at regulating temperature. In addition to its use in cars, antifreeze is also found in other applications, such as in refrigeration systems and solar water heating. It is important to use the correct type of antifreeze for your vehicle, as different formulations can affect performance and engine longevity.