Cloud Computing,Development of Internet-based

Cloud Computing is the most important trend in the software industry of the decade. “Cloud computing” refers to delivering hosted services over the Internet. The services tend to be divided into three categories: infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS), and software-as-a-service (SaaS). A cloud service has characteristics that differentiate it from traditional hosting.

If a service provider chooses public cloud resources to create their own private cloud, the result is a virtual private cloud.The origin of the expression cloudcomputing is obscure, but it appears to derive from the practice of using drawings of stylized clouds to denote networks in diagrams of computing and communications systems. In his 1966 book The Challenge of the Computer Utility, the Canadian electrical engineer Douglas F. Parkhill predicted that the computer industry would come to resemble a public utility “in which many remotely located users are connected via communication links to a central computing facility.”

Cloud is the result of a convergence of three worlds: consumers, business and technology. The first is elasticity, which means that resources can be provisioned and de-provisioned in real time to meet workload demands. The final attribute is ubiquity because services from the cloud are available via the worldwide Web. This enables user interfaces that go beyond traditional workstations to include cell phones and other appliances.

Cloud computing encompasses a number of different services. Traditional software companies, including Microsoft Corporation, Apple Inc., Intuit Inc., and Oracle Corporation, have also introduced cloud applications.Cloud-computing companies either charge users for their services, through subscriptions and usage fees, or provide free access to the services and charge companies for placing advertisements in the services.

Data centres and privacy

Construction of the large data centres that run cloud-computing services often requires investments of hundreds of millions of dollars. The centres typically contain thousands of server computers networked together into parallel-processing or grid-computing systems.

Using a cloud computing environment generally requires you to send data over the Internet and store it on a third-party system. The privacy and security risks associated with this model must be weighed against alternatives.