Applying thermal paste to a processor chip like intel or amd helps for not overheating. It maintains a range of temperature so that it will not overheat. This is also the most commmon cause why your computer begins to freeze or hangs up suddenly. When your computer or laptop begins to process an application very slowly and you noticed when you touch the cpu part, this is one of the reason. So overheating of the cpu or the gpu for the graphics. And applying a thermal paste to it is one solution. So here is a video on how to apply thermal paste to your cpu or gpu unit.
Correct Way of Applying Thermal Paste
I hope this video on applying thermal paste on your computer's cpu or graphics unit guides you with this tutorial.