Cloud Computing  Cloud computing is a term used to refer to a model of network computing where a program or application runs on a connected server or servers rather than on a local computing device such as a PC, tablet or smartphone.  Like the traditional client-server model or older mainframe computing, a user connects with a server to perform a task.client-server modelmainframe computing  The difference with cloud computing is that the computing process may run on one or many connected computers at the same time, utilizing the concept of virtualization.virtualization

Cloud Computing  With virtualization, one or more physical servers can be configured and partitioned into multiple independent "virtual" servers, all functioning independently and appearing to the user to be a single physical device.partitioned  In more detail, cloud computing refers to a computing hardware machine or group of computing hardware machines commonly referred as a server or servers connected through a communication network such as the Internet, an intranet, a local area network (LAN) or wide area network (WAN).servercommunication networkInternetintranetlocal area network (LAN)wide area network (WAN)  Any individual user who has permission to access the server can use the server's processing power to run an application, store data, or perform any other computing task.

Cloud Computing  The major models of cloud computing service are known as software as a service, platform as a service, and infrastructure as a service. These cloud services may be offered in a public, private or hybrid network.software as a serviceplatform as a serviceinfrastructure as a service  Google,Amazon,IBM,OracleCloud, Rackspace, Salesforce, Zoho and Microsoft are some well-known cloud vendors. GoogleAmazonIBMOracleCloudRackspaceSalesforceZoho Microsoft  According to a 2008 IEEE paper, “Cloud Computing is a paradigm (Model) in which information is permanently stored in servers on the internet and cached temporarily on clients that include desktops, entertainment centers, table computers, notebooks, wall computers, hand-helds, sensors, monitors, etc.”IEEE

Cloud Computing  In simple, we could describe cloud as internet, and cloud computing as large systems that are connected in public or private networks.  For example, a company could have computers that connect to an application and allow workers to log in into a Web-based service which hosts all the programs the user would need for his or her job.  In this system, a company will not have to provide the right hardware and software for every employee hired to do their jobs. Hence it could reduce cost, and make data or application more easily obtained and ubiquitously accessed

Cloud Computing

Cloud computing shares characteristics with: Client–server modelClient–server model — Client–server computing refers broadly to any distributed application that distinguishes between service providers (servers) and service requestors (clients). [38]distributed application [38] Grid computingGrid computing — "A form of distributed and parallel computing, whereby a 'super and virtual computer' is composed of a cluster of networked, loosely coupled computers acting in concert to perform very large tasks."clusterloosely coupled Mainframe computerMainframe computer — Powerful computers used mainly by large organizations for critical applications, typically bulk data processing such as: census; industry and consumer statistics; police and secret intelligence services; enterprise resource planning; and financial transaction processing.censusenterprise resource planningtransaction processing

Cloud Computing Utility computing — The "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility, such as electricity." Utility computing resources Peer-to-peer — A distributed architecture without the need for central coordination. Participants are both suppliers and consumers of resources (in contrast to the traditional client– server model). Peer-to-peer

History of Cloud Computing One of the first questions asked with the introduction of a new technology is: “When was it invented?” Other questions like “When it was first mentioned?” and “What are the prospects for its future?” are also common. When we think of cloud computing, we think of situations, products and ideas that started in the 21st century. This is not exactly the whole truth. Cloud concepts have existed for many years.

History of Cloud Computing It was a gradual evolution that started in the 1950s with mainframe computing. Multiple users were capable of accessing a central computer through dumb terminals, whose only function was to provide access to the mainframe. Because of the costs to buy and maintain mainframe computers, it was not practical for an organization to buy and maintain one for every employee. Nor did the typical user need the large (at the time) storage capacity and processing power that a mainframe provided. Providing shared access to a single resource was the solution that made economical sense for this sophisticated piece of technology.

History of Cloud Computing Cloud computing has evolved through a number of phases which include grid and utility computing, application service provision (ASP), and Software as a Service (SaaS). Cloud computing But the overarching concept of delivering computing resources through a global network is rooted in the 1960’s.overarching concept The idea of an "intergalactic computer network" was introduced in the sixties by J.C.R. Licklider, who was responsible for enabling the development of ARPANET (Advanced Research Projects Agency Network) in 1969."intergalactic computer network"sixties by J.C.R. Licklider His vision was for everyone on the globe to be interconnected and accessing programs and data at any site, from anywhere

History of Cloud Computing After some time, around 1970, the concept of virtual machines (VMs) was created. Using virtualization software like VMware, it became possible to execute one or more operating systems simultaneously in an isolated environment. Complete computers (virtual) could be executed inside one physical hardware which in turn can run a completely different operating system. The VM operating system took the 1950s’ shared access mainframe to the next level, permitting multiple distinct computing environments to reside on one physical environment. Virtualization came to drive the technology, and was an important catalyst in the communication and information evolution.

History of Cloud Computing In the 1990s, telecommunications companies started offering virtualized private network connections. Historically, telecommunications companies only offered single dedicated point–to-point data connections. The newly offered virtualized private network connections had the same service quality as their dedicated services at a reduced cost. Instead of building out physical infrastructure to allow for more users to have their own connections, telecommunications companies were now able to provide users with shared access to the same physical infrastructure.

History of Cloud Computing One of the first milestones in cloud computing history was the arrival of Salesforce.com in 1999, which pioneered the concept of delivering enterprise applications via a simple website.cloud computing history The services firm paved the way for both specialist and mainstream software firms to deliver applications over the internet. The next development was Amazon Web Services in 2002, which provided a suite of cloud-based services including storage, computation and even human intelligence through the Amazon Mechanical Turk.Amazon Mechanical Turk Then in 2006, Amazon launched its Elastic Compute cloud (EC2) as a commercial web service that allows small companies and individuals to rent computers on which to run their own computer applications.

History of Cloud Computing "Amazon EC2/S3 was the first widely accessible cloud computing infrastructure service,“ which provides its SaaS online video platform to UK TV stations and newspapers. Another big milestone came in 2009, as Web 2.0 hit its stride, and Google and others started to offer browser- based enterprise applications, though services such as Google Apps.Google Apps SoftLayer is one of the largest global providers of cloud computing infrastructure. SoftLayer IBM already has platforms in its portfolio that include private, public and hybrid cloud solutions. The purchase of SoftLayer guarantees an even more comprehensive infrastructure as a service (IaaS) solution. While many companies look to maintain some applications in data centers, many others are moving to public clouds.

History of Cloud Computing The following list briefly explains the evolution of cloud computing: Grid computing: Solving large problems with parallel computing Utility computing: Offering computing resources as a metered service SaaS: Network-based subscriptions to applications Cloud computing: Anytime, anywhere access to IT resources delivered dynamically as a service