Cloud computing comes into focus when there is a need for a way in IT to increase capacity or add capabilities on the fly without investing in new infrastructure, training new personnel, or licensing new software. Cloud computing encompasses any subscription-based or pay-per-use service that, in real-time over the Internet, extends existing capabilities of IT. Cloud computing is an expression used to describe various computing concepts that involve a large number of computers connected through a real-time communication network such as the Internet. The three known Cloud services models are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). The Iaas model offers the hardware virtualization resources such as processing, networking, and storage services. Correspondingly, the PaaS model provides the computing platform over the network for developing, processing, and managing the required applications of the users. The SaaS offers the users access to the software application in the Cloud environment over the internet.