Electrochromic materials change color or opacity when an electric current is applied. This property allows them to be used in various applications, such as smart windows, which can adjust their tint to control light and heat entering a building. This technology helps improve energy efficiency and privacy. In addition to windows, electrochromic technology is also used in devices like smart mirrors and automotive rearview mirrors. These materials can switch between transparent and tinted states, enhancing user comfort and safety. The development of electrochromic systems continues to advance, promising even more innovative uses in the future.