What Is Cloud Computing

Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowchart and diagrams.A cloud computing service has three distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.Infrastructure-as-a-Service like Amazon Web Services provides virtual server instances with unique IP addresses and blocks of storage on demand. Customers use the provider's application program interface (API) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required.Amazon Elastic Compute Cloud (EC2):Amazon's EC2 is a cloud computing service that allows users to deploy and run their applications on rented virtual computers.Users can boot what are called Amazon Machine Images and create an instance, also known as a virtual machine, and pay for the amount of computing power they need by the hour. Amazon EC2 uses Xen virtualization, and the service allows users to adapt to changing performance and capacity needs with an auto-scaling function.
Amazon Simple Storage ServiceAmazon's S3 is a cloud storage service that provides scalable, unlimited online archiving and backup for Amazon Web Services users. As of early March, Amazon S3 had stored more than 100 billion objects.Cloud BackupCloud backup is the concept of sending copies of your data to an off-site server for backup storage. Enterprises have proven reluctant to adopt cloud backup for pertinent data, as security concerns and fears about storing critical information in the cloud persist. Several prominent cloud backup services are Amazon S3, Asigra and EMC's Mozy.Cloud CartographyCloud cartography is a strategy designed to pinpoint the physical locations of Web servers hosted on a third-party cloud computing service. The goal would be to map the service provider's infrastructure in order to identify where a particular virtual machine resides. This scheme was discovered during a study carried out on Amazon Web Services by researchers from MIT and the University of California, San Diego.Windows Azure:Windows Azure is a cloud services operating system that serves as the development, service hosting and service management environment for the Windows Azure platform. Windows Azure provides developers with on-demand compute and storage to host, scale, and manage web applications on the internet through Microsoft datacenters. This session introduces the concepts of Windows Azure platform including compute and storage. You will learn how to design, develop, debug and deploy your first Cloud application using Visual Studio and Azure Tools.

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