Resistivity is a property of materials that quantifies how strongly they resist the flow of electric current. It is measured in ohm-meters (Ω·m) and varies depending on the material's composition and temperature. Conductors, like metals, have low resistivity, allowing electricity to flow easily, while insulators, such as rubber, have high resistivity, preventing current flow. The resistivity of a material can be influenced by factors such as temperature and impurities. For example, the resistivity of copper increases with temperature, which can affect the performance of electrical components. Understanding resistivity is essential in designing circuits and selecting materials for electrical applications.