Technically, the concept of cloud computing is far from new, it has even been present for decades. The first traces of it can be found in the 1960s, when John McCarty claimed that this computer processing power would be accessible to the public in the future. The term itself appeared more commonly around the end of the twentieth century and it would seem thatamazon.Com or one of the first to have assembled data centers and provides access to customers. Companies like IBM and Google as well as several universities only began to take a serious interest in it around 2008, when cloud computing became a fashionable concept. Realizing what they could do with all this power, many companies then began to show some interest, then to exchange their old infrastructures and internal applications for what are called "pay per-use service".