Thermoelectric coolers, also known as Peltier devices, 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, when energized, transfer heat from one side to the other. This allows one side to become cold while the opposite side heats up. These devices are commonly used in various applications, such as refrigeration, computer cooling, and temperature control in small electronic devices. They are compact, lightweight, and have no moving parts, making them reliable and easy to integrate into different systems.