A case fan is a small, electric fan used in computer cases to improve airflow and cooling. It helps to dissipate heat generated by components like the CPU and GPU, ensuring that the system operates efficiently and prevents overheating. Case fans come in various sizes and speeds, typically measured in RPM (revolutions per minute). These fans can be installed in different locations within the computer case, such as the front, back, or side panels. Proper placement is essential for optimal airflow, as it creates a balance between intake and exhaust. Maintaining a cool environment is crucial for the longevity of computer components like the motherboard and power supply.