Case fans are essential components in computer systems that help regulate temperature by promoting airflow within the computer case. They draw in cool air from the outside and expel warm air generated by the CPU, GPU, and other hardware. This cooling process prevents overheating, which can lead to hardware damage and reduced performance. Typically, case fans come in various sizes and speeds, measured in RPM (revolutions per minute). They can be installed in different locations within the case, such as the front, back, or side panels, to optimize airflow. Proper placement and configuration of case fans are crucial for maintaining an efficient cooling system.