An intercooler is a device used in internal combustion engines, particularly in turbocharged or supercharged systems. Its primary function is to cool the compressed air before it enters the engine's combustion chamber. By lowering the air temperature, the intercooler increases air density, allowing for more oxygen to enter the engine, which can enhance performance and efficiency. Intercoolers can be classified into two main types: air-to-air and air-to-water. The air-to-air intercooler uses ambient air to cool the compressed air, while the air-to-water intercooler uses a liquid coolant. Both types help prevent engine knock and improve overall engine performance.