Inside be quiet!
The purpose of fans should be quite obvious: Their perpetual rotation keep the air in motion - which moves cool air to an object or hot air away from one. But what is a “PWM fan”? And what does it do differently than its “non-PWM” sibling?
PWM fans can be used everywhere: For cooling the CPU and the case, or on top of a radiator. The control can be handled by using bespoke tools in the operating system or the BIOS/UEFI – or by using the switches on top of our cases. If you don’t care about manual control you can also let the system take care of itself – modern motherboards work within safe specifications which will cool your computer reliably at all times.