Eli5: How do heat sinks work?

Question

Curious how they work. Why do they look like lots of layers of fins.

In: 6

Answer 1

Use a highly conductive material to make shapes with maximum surface area to maximize heat transfer to the surrounding air. Easiest shape to manufacture is skivving a large number of thin fins.

If you need more cooling, force air into the fins to displace the warm air with fresh, cool air.