This section explains in basic terms the principals that are used to create the refrigeration effect. Graphics and animation's are used in an attempt to make it easy to understand the concepts involved.  First of all, did you know that there is no such thing as cold? You can describe something as cold and everyone will know what you mean, but cold really only means that something contains less heat than something else. All there really is, is greater and lesser amounts of heat. The definition of refrigeration is The Removal and Relocation of Heat. So if something is to be refrigerated, it is to have heat removed from it. If you have a warm can of pop at say 80 degrees Fahrenheit and you would prefer to drink it at 40 degrees, you could place it in your fridge for a while, heat would somehow be removed from it, and you could eventually enjoy a less warm pop. (oh, all right, a cold pop.) But lets say you placed that 40 degree pop in the freezer for a while and when you removed it, it was at 35 degrees. See what I mean, even "cold" objects have heat content that can be reduced to a state of "less heat content". The limit to this process would be to remove all heat from an object. This would occur if an object was cooled to Absolute Zero which is -273º C or -460º F. They come close to creating this temperature under laboratory conditions and strange things like electrical superconductivity occur.