Cloud computing is an emerging model where users can gain access to their applications from anywhere through their connected devices. A simplified user interface makes the infrastructure supporting the applications transparent to users. The applications reside in massively-scalable data centers where compute resources can be dynamically provisioned and shared to achieve significant economies of scale. A strong service management platform results in near-zero incremental management costs when more IT resources are added to the cloud. The proliferation of smart mobile devices, high speed wireless connectivity, and rich browser-based Web 2.0 interfaces has made the network-based cloud computing model not only practical but also a source of reduced IT complexity.
Players across the IT industry have announced cloud computing efforts of varying shapes and sizes, leading analysts to attempt to identify various characteristics, such as infrastructure outsourcing, software as a service, and next generation distributed computing, to describe these efforts.
Keywords: Clouds, Grid computing, Cloud Storage, SaaS, Server Virtualization, Data Center
1. Introduction
Cloud computing comes into focus only when we think about what IT always needs: a way 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 IT's existing capabilities.
The term Cloud Computing derives from the common depiction in most technology architecture diagrams, of the Internet or IP availability, using an illustration of a cloud. The computing resources being accessed are typically owned and operated by a third-party provider on a consolidated basis in Data Center locations. Target consumers are not concerned with the underlying technologies used to achieve the increase in server