Electrical conductivity is a measure of a material's ability to conduct electric current. It is determined by the presence of free electrons or ions that can move through the material. Metals, such as Copper and Aluminum, are known for their high electrical conductivity, making them ideal for electrical wiring and components. In contrast, insulators like Rubber and Glass have low electrical conductivity, preventing the flow of electricity. The conductivity of a material can be influenced by factors such as temperature and impurities, which can either enhance or diminish its ability to conduct electricity.