Peltier devices, also known as thermoelectric coolers, are electronic components that create a temperature difference when an electric current passes through them. They consist of two different types of semiconductor materials, which are joined together. When electricity flows through these materials, one side absorbs heat and cools down, while the other side releases heat and warms up. These devices are commonly used in various applications, such as refrigeration, computer cooling, and temperature control in scientific instruments. They are valued for their compact size, reliability, and ability to provide precise temperature regulation without moving parts.