Peltier modules are also commonly referred to as thermoelectric modules, thermoelectric coolers or tech modules. They are typically rather non-descript, but are quite powerful. Of course, there are other styles, such as an entire Peltier cooling unit and other multi-stage devices. However, the basic premise is the same as you apply a voltage across these terminals as the current through the device moves heat from one side to the other.
A full explanation can be seen in the video below.