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.

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.

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.

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).

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 ComputingThe 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.

Google,Amazon,IBM,OracleCloud, Rackspace, 

Salesforce, Zoho and Microsoft are some well-known

cloud vendors .

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.”

Cloud ComputingIn 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 ComputingCloud computing shares characteristics with:Client–server model — Client–server computing refers broadly to any distributed application that distinguishes between service providers (servers) and service requestors (clients).[38]

Grid 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."Mainframe 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.

Cloud ComputingUtility computing — The "packaging of 

computing resources, such as computation and storage, as a metered service similar to a traditional public utility, such as electricity."

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).

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).

But the overarching concept of delivering computing resources through a global network is rooted in the 1960’s.

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.

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.

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.

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.

SoftLayer is one of the largest global providers of cloud computing infrastructure.

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