Every CPU comes equipped with its own cooling system. The CPU comes  with a fan and heatsink to cool it down. However this fan and heatsink may not be enough to cool down the CPU during high

demanding tasks. CPUs also have their optimum working temperatures making them also come equipped with a cooling controller. The fan speeds are controlled as needed. 

When the temperature of a CPU is very high it can lead to an irrepairable damage. Also the CPU will begin to malfunction or run slowly at very high temperatures. Most computers come equipped with sensors that detect a very high temperature CPU and shut off the computer abruptly to protect the CPU from damage.

The more demanding tasks the CPU is made to analyse, the more temperature it will have. In high demanding games and video editing work you will most likely need an extra CPU cooling system, otherwise at very high temperatures, the CPU may malfunction and the computer will shut off abruptly which can cause damage to hardware and software components.

The two types of extra CPU cooling system you might need are the air-cooled cooling system and the water cooled system.

The air CPU cooler is just an advanced fan and heatsink that you can attach to your CPU for better cooling efficiency.

The water CPU cooler is the better way of cooling your CPU, it consists of a fan and radiator that you can attach to your PC. Because it uses water as the coolant it is far more efficient than an air cooled CPU. However it comes at the higher cost. But if you are using a very powerful CPU and usually play a demanding games or edit high definition videos or run high demanding 3D applications, a computer to function optimally and last longer, consider getting water cooled CPU