A Peltier device is a small electronic component that can create a temperature difference when an electric current passes through it. It consists of two different types of semiconductor materials, which are joined together. When electricity flows through the device, one side becomes hot while the other side becomes cold, allowing it to either heat or cool an object. These devices are commonly used in various applications, such as coolers, refrigerators, and thermoelectric generators. They are valued for their compact size and ability to provide precise temperature control without moving parts, making them efficient and reliable for many cooling and heating tasks.