Cloud computing, has its roots in late of 2007, but is becoming one of the next IT industry hot topics because it promotes the idea that users can move their data and applications to a remote “Cloud” and then they can have access in a simple and pervasive way.
This means that cloud computing offers flexible dynamic IT infrastructures and configurable software services (Armbrust et al, 2009).
There are several definitions about Cloud Computing which refer to the applications delivered as services, hardware, software that provide those services. The Cloud is a platform or infrastructure that enables the execution of services or applications following the requirements.
There are main types of clouds: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS),
Armbrust, M; Fox, A; Griffith, R; Joseph, AD; Katz, RH; Konwinski, A; Lee, G; Patterson, DA; Rabkin, A; Stoica, I &Zaharia, M (2009), ‘Above the Clouds: A Berkeley View of Cloud Computing’. Technical Report No.UCB/EECS-2009-28 – available at http://goo.gl/Pc5G