It’s a law of science that if you smear a little amount of water on skin, after a while it will evaporate and you will feel coldness on the skin. The reason why it happens is that to turn water into vapor, energy is used. Evaporating water gets this energy (heat) from the body itself. Hence, the part losing heat as energy goes cold. The same principle is applied in a refrigerator. Here, the liquid called chlorofluorocarbon (CFC) evaporates in a thin tube; that is, turns into gas. While doing so CFC absorbs the heat in the refrigerator, and thus the interior is bound get cold. The CFC gas then moves towards the tangle of tubes in the rear part of the refrigerator, where it is turned again into liquid using compressor and loses its heat to the air. This liquid again absorbs the heat in the refrigerator to turn into gas.
Now remains the position of the icebox. The answer of the question related to icebox too is very interesting. It is better to keep an ice-compartment, i.e. icebox on top, because in a refrigerator more heat is accumulated in top, hence the first squirt of cold liquid should be made there. This is why it is arranged for CFC turned into liquid with compressor to flow towards the top directly. When it is inevitable to do so and also the liquid entering the top level is super cold, then why not use it to benefit? Turning water into ice necessitates removing all natural heat off it – and it is quite natural that this can be done only using the freshly entered freezing-cold liquid CFC.