Here's why:

* Conduction is the transfer of heat energy through direct contact between substances. This transfer occurs at the molecular level.

* Heat energy is transferred through vibrations of atoms and molecules. The hotter substance has faster vibrating molecules, and these vibrations are transferred to the molecules of the cooler substance, increasing their vibration and thus their temperature.

* The molecules themselves do not move from one place to another. They simply pass energy along through their vibrations.

Think of it this way: Imagine a row of dominoes. When you push the first domino, it falls and knocks over the next one, which knocks over the next, and so on. The dominoes themselves are not moving from one end of the row to the other, but the energy of the push is transferred down the row.

In contrast, convection involves the movement of matter. Convection is the transfer of heat through the movement of fluids (liquids or gases). The warmer fluid rises, and the cooler fluid sinks, creating a cycle of heat transfer.