Introduction 
Cloud computing means using the computing resources both hardware and software, that are delivered as a service over Internet. In other words, computer and software services necessary for computing works provided via the internet is called cloud computing.

When we think about the need of IT, cloud computing comes into focus like the requirement of a way to increase or add capabilities on the fly without investing in new infrastructure, training new personnel, licensing new software etc. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends IT’s existing capabilities.