Cloud computing refers to storing and accessing data and programs over the Internet instead of a computer's hard drive. It allows users to access files and applications from any device. There are three categories of cloud computing: Infrastructure as a Service, Platform as a Service, and Software as a Service. Cloud computing works by hosting information on remote servers that users can access through the web or a software application from any location. Common examples of cloud computing include webmail, online photo storage, and social networking sites.

1. CLEARING UP CLOUD COMPUTINGBy Nicole SiegelMay 19, 2010

2. WHAT IS CLOUD COMPUTING?

3. WHAT IS A CLOUDThe term "cloud" is used as a metaphor for the Internet.The cloud is a batch of computers called data centers or servers that hold your information (files, images, videos, etc.) and can be located anywhere. Some claim that the phrase cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.

4. SO WHAT IS CLOUD COMPUTING?

5. CLOUD COMPUTING….When data or software applications are not stored on a user’s computer, but rather are accessed through the web from any device at any location.The server and computing environment exist in a virtual sense, and aren’t tied to any one particular machine. Files and applications are basically floating around in a “cloud of resources”, making the hardware less important.Cloud computing customers do not own the physical infrastructure but rather rent usage from a third-party provider (there are paid and unpaid models).Also known as grid computing, utility computing, software as a service, Internet-based applications, autonomic computing, peer-to-peer computing and remote processing.

6. A BRIEF HISTORYYears ago, computing was largely centralized. Users accessed information and programs on mainframe computers (such as Microsoft and Adobe).The underlying concept of cloud computing dates back to 1960, when John McCarthy declared that “computation may someday be organized as a public utility.”Amazon played a key role in the development of cloud computing, providing access to their systems through Amazon Web Services (remote computing services).Recent evolutions in information technology (and the growth in broadband access) have led to a more distributed computing environment.

7. 3 CATEGORIESInfrastructure-as-a-Service (IaaS)Outsources the equipment used to support operations, including storage, hardware, servers and networking components. The service provider owns the equipment and is responsible for housing, running and maintaining it.Examples: Amazon EC2, Rackspace CloudPlatform-as-a-Service (PaaS)Delivers operating systems and application platforms over the Internet without downloads or installation.Examples: Google App Engine, Force.comSoftware-as-a-Service (SaaS)Delivers software as a service over the Internet, eliminating the need to install and run on a computer.Examples: Gmail, Wordpress.com

8. HOW IT WORKS

9. HOW IT WORKSImagine that the cloud consists of layers — the back-end layers and the front-end or end-user layers.When email is accessed on Gmail for example, software is running on the front-end of a cloud. The same is true with access to Facebook accounts.The back-end consists of the hardware and the software architecture that fuels the interface you see on the front-end.

10. HOW IT WORKSCloud computing works by hosting information on computers out ‘in the cloud’. Work is then done in a cloud since it is not necessary to store software or files on an individual computer. Typical cloud computing providers deliver common business applications online which are accessed from another web service or software like a web browser, while the software and data are stored on servers.Web-based programs, like Hotmail, Gmail, Google Docs and Facebook run in the browser and contain data which exists outside of a computer, or "in the cloud."

11. EXAMPLES

12. EXAMPLESMany people have already transitioned to using a cloud environment without even realizing it:Webmail services such as Hotmail, Gmail and Yahoo! Online photo storage/albums such as Snapfish, Picassa and KodakGoogle documentsVideo upload sites such as YouTube, VimeoHard drive back-up sitesSocial bookmarkingPresentation storageSocial networking sites such as Facebook

13. WHO IS USING IT

14. WHO IS USING ITWiFi connectors are enthusiastic and are the most avid adopters.Younger Internet users are more inclined than older ones to use services or applications that require personal data to be stored online.A large company that has employees in numerous locations running specialized software to carry out data-intensive tasks.Business travelers needing access while away from their computer.Students looking to work remotely.

15. ADVANTAGES

16. ADVANTAGESAccessibilityAgilityCost effectiveEasy and convenientEnvironmentally friendlyFlexibilityLow MaintenanceReliabilityShareability

17. DISADVANTAGES

18. DISADVANTAGESInconsistentLack of privacyLearning curveLess control over personal informationLiabilityNew technologyReliant on InternetSecurity issues

19. WHAT IT ALL MEANS

20. Future of Cloud ComputingCloud computing is changing the way we use the web and store files.With broadband Internet, the need to have hardware/software run on a computer is becoming less essential.According to Steve Ballmer, "It's the next step, it's the next phase, it's the next transition.”John Herlihy of Google Europe has essentially mirrored those thoughts, calling the desktop an item that will be "irrelevant" in three years. Why? Largely because most everything you'll need a tower for will be available via a mobile or the web.

21. Future of Cloud ComputingWe are transitioning from being very ‘personal hardware dependent’ to a world where resources are shared among the masses. For businesses, cloud computing translates to greater efficiencies and collaboration (and IT staff and budget reductions). For the average internet user, we'll start seeing a more networked world in which we'll be using our computers and mobile devices to easily access information stored elsewhere.

22. REFERENCEShttp://aws.amazon.com/ec2/http://blog.monitis.com/index.php/2009/09/09/3-types-of-cloud-computing-services/http://cloudcomputing.sys-con.com/node/581961http://www.engadget.com/2010/03/05/steve-ballmer-emphasizes-importance-of-the-cloud-google-pretty/ http://mashable.com/2008/08/19/cloud-computing-defined/http://www.pewinternet.org/topics/Cloud-Computing.aspxhttp://searchcloudcomputing.techtarget.com/sDefinition/0,,sid201_gci1287881,00.html