A visible example of conduction is when a person takes a pencil or a pen or a marker in their hand, holds it tightly for 30 seconds, two minutes, let it go, and notices that the temperature rises in the marker or the pencil. And this occurs because there's an energy transfer or flow of energy from my body, from my hand, from my palm into this marker, thereby raising the temperature of this marker. That is conduction. And it only occurs when there is physical contact. So when people talk about conduction, they usually talk about energy flow or the rate of energy flow within the system. In this situation outlined here, I have a hot system, a cold system, the physical contact, the bridge that's connecting the two systems, okay?