A Peltier cooler is a a type of cooler that uses the peltier element. The peltier element is a tool composed of no moving elements that can used to heat, cool, or generate electricity.  The solidity of these elements make the device last long. The device is most of time made from two side (hot and cold). The difference between the side (70 degree Celsius) make it easy to cool devices.

 

 

Here is a video on how Peltier cooler works:

 

 

 

 

 

 

 

http://www.survival-manual.com/electricity/peltier-elements.php

http://www.heatsink-guide.com/peltier.htm