Question

Define conduction. What is thermal conductivity?

Answer 1

Conduction is the process by which heat or electricity is directly transmitted through the material of a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.
Thermal conductivity (often denoted $k,\lambda$, or κ) is the property of a material to conduct heat. Heat transfer occurs at a lower rate across materials of low thermal conductivity than across materials of high thermal conductivity.