Mar 312012

Cloud Computing is a technology which uses internet (or the public Internet) and central servers to provide computation, software, data access and storage. End user does not require any knowledge of the physical location and configuration of the system that delivers the services. It provides an always available service for the users, provided that the user takes care of the last mile connectivity.

With cloud computing, user can perform routine computer tasks anywhere, at any time, without installing applications on the local computer. All users need a computer connected to the internet (or public Internet as the case may be) and a compatible application (say, a browser) running on the computer.

How Cloud computing works: Cloud means a grid of computing machines that deliver the solution to the customer. Most websites and server-based applications run on particular computers or servers. The applications are stored on these cloud platforms and accessed by the user without knowing specific server configurations.

Types of cloud computing: Based on where the cloud is hosted also referred as Cloud computing Deployment models:

Public Cloud: This is standard computing model. The computing infrastructure can be shared among several people or organizations with similar requirements. The user need not worry about the stability or up-time of a specific machine in the cloud-computing infrastructure and it is transparent to the user. Several public cloud services offered free of charge to Internet users and discussed in the article.

Private Cloud: Computing architecture is dedicated to the customer and is not shared with other organizations and managed internally or by a third-party. A private cloud may be hosted internally or externally. They are expensive and are considered more secure than Public Clouds.  RackSpace cloud computing is among the first to introduce cloud computing, and is widely used by many organizations due to robust and effective security mechanism that comes with their service.

Community Cloud: Community cloud shares infrastructure between several organizations from a specific community with common concerns (security, compliance, jurisdiction, etc.). A Community cloud may be hosted and managed managed internally or by a third-party. The costs are borne by several organizations, thus reducing the running cost significantly and providing better security and resources compared with a Public cloud.

Hybrid Cloud: Hybrid cloud is a combination of two or more clouds (private, community, or public) that remain unique entities but are bound together, offering the benefits of multiple deployment models. It can also be defined as multiple cloud systems that are connected in a way that allows programs and data to be moved easily from one deployment system to another.

For a complete article on Cloud Computing, please visit The contents of the article include Introduction to virtualization, description of cloud computing, differences between virtualization and cloud computing, different types of cloud models, and some prominent cloud service providers including RackSpace, Google, Amazon, and Microsoft.