A heat sink is an object that cools down after being heated up, in order to prevent overheating or damage from excess heat by absorbing some of the energy through conduction and convection. This allows for more efficient use of materials since only their surface layers are being constantly reheated during operations while deeper parts stay at lower temperatures allowing them to last longer without breaking down prematurely due increased exposure over time when not properly cooled. Heat sinks can be made out many different types of material including metal, plastic/resin bonded fiberglass, etc., with each having its own benefits depending on what they are attached too (or built into).