What does thermal conductivity indicate about a material?

Thermal conductivity indicates a material's ability to conduct heat. This property quantifies how effectively heat is transferred through the material when there is a temperature difference. In practical terms, materials with high thermal conductivity allow heat to flow through them easily, making them good conductors of heat. Metals, for instance, typically have high thermal conductivity, which is why they feel warm to the touch when exposed to heat sources.

On the other hand, materials with low thermal conductivity are considered insulators, as they do not allow heat to pass through easily, helping to retain heat within an environment. This distinction is essential in applications like thermal insulation, where one aims to minimize heat transfer. Therefore, understanding thermal conductivity is crucial for selecting materials in various engineering and construction contexts where temperature control is vital.