A case fan and a CPU fan serve different purposes in a computer system.

A case fan is designed to cool the overall temperature inside the computer case by moving air in and out of the case. It helps to prevent overheating of components, such as the graphics card and power supply, and also improves the lifespan of the system by keeping the internal temperature within safe limits. Case fans come in different sizes, speeds, and types, including axial fans, centrifugal fans, and PWM fans.

On the other hand, a CPU fan is a specialized fan that is attached to the CPU heatsink to cool the processor. The CPU generates a lot of heat during its operation, and a CPU fan helps to dissipate this heat by drawing air through the heatsink and away from the CPU. CPU fans come in different sizes and designs, including air-based and liquid-based cooling systems.

In summary, a case fan is designed to cool the entire computer system, while a CPU fan is designed to specifically cool the processor. Both fans play an important role in maintaining the temperature and overall performance of a computer system.