What is thermal conductivity

Thermal conductivity ($k$) is a material property that quantifies its ability to conduct heat. It represents the rate at which heat energy is transferred through a unit thickness of the material per unit area per unit temperature difference. Its SI unit is Watts per meter Kelvin ($\text{W/(m}\cdot\text{K)}$). Materials with high thermal conductivity (like metals) transfer heat efficiently, while those with low thermal conductivity (like insulation materials) are poor heat conductors.