Definition:
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 flowcharts and diagrams.
A cloud 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 instanceAPI)
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. Because this pay-for-what-you-use model resembles the way
electricity, fuel and water are consumed, it's sometimes referred to as utility computing.
Platform-as-a-service in the cloud is defined as a set of software and product development
tools hosted on the provider's infrastructure. Developers create applications on the provider's
platform over the Internet. PaaS providers may use APIs, website portals or gateway software
installed on the customer's computer. Force.com, (an outgrowth of Salesforce.com) and
GoogleApps are examples of PaaS. Developers need to know that currently, there are not
standards for interoperability or data portability in the cloud. Some providers will not allow
software created by their customers to be moved off the provider's platform.
In the software-as-a-service cloud model, the vendor supplies the hardware infrastructure, the
software product and interacts with the user through a front-end portal. SaaS is a very broad
market. Services can be anything from Web-based email to inventory control and database
processing. Because the service provider hosts both the application and the data, the end user
is free to use the service from anywhere.
Cloud computing is a technology that uses the internet and central remote servers to
maintain data and applications. Cloud computing allows consumers and businesses to use
applications without installation and access their personal files at any computer with internet
access. This technology allows for much more efficient computing by centralizing storage,
memory, processing and bandwidth.
A simple example of cloud computing is Yahoo email or Gmail etc. You dont need a
software or a server to use them. All a consumer would need is just an internet connection
and you can start sending emails. The server and email management software is all on the
cloud ( internet) and is totally managed by the cloud service provider Yahoo , Google etc.
The consumer gets to use the software alone and enjoy the benefits. The analogy is , 'If you
only need milk , would you buy a cow ?' All the users or consumers need is to get the
benefits of using the software or hardware of the computer like sending emails etc. Just to get
this benefit (milk) why should a consumer buy a (cow) software /hardware ?
Cloud computing is broken down into three segments: "applications," "platforms," and
"infrastructure." Each segment serves a different purpose and offers different products for
businesses and individuals around the world. In June 2009, a study conducted by VersionOne
found that 41% of senior IT professionals actually don't know what cloud computing is and
two-thirds of senior finance professionals are confused by the concept,[1] highlighting the
young nature of the technology. In Sept 2009, an Aberdeen Group study found that
disciplined companies achieved on average an 18% reduction in their IT budget from cloud
computing and a 16% reduction in data center power costs.
List of cloud computing providers
Service providers
Cloud computing
Amazon
ElasticHosts
Microsoft Azure
Logicworks
Google.[1][2]
Joyent[3]
Jitscale
Linode
Maximizer Software
Rackspace Cloud
Salesforce
Skytap
Cloud storage
Amazon S3[4][5]
Box.net
Dropbox
Nirvanix
Spideroak
Windows Azure
Cloud Faxing Providers
Graphnet, Inc[6]
Cloud platforms
Abiquo[7]
CA 3Tera AppLogic
Cloud.com (formerly VMOps[8])
ElasticHosts ElasticStack[9][10]
Enomaly ECP
Eucalyptus
Flexiant Extility[11]
Gluster
InContinuum CloudController[12]
Nimbus (cloud computing)
Mezeo (Storage only)[13]
OnApp[14]
OpenNode[15]
OpenStack.org
Parallels
Joyent
VMware vCloud
Witsbits Go Cloud[16]
Zimory[17]
Multi-cloud services and tools
API Translators
Deltacloud, API Translator service running on your local machine [18]
Libcloud, a standard client library for many popular cloud providers, written in python and
java[19]
Dashboards
Cloudkick, unified cloud dashboard/monitoring covering 8 public clouds[20]
Geckoboard
Nimsoft, unified cloud dashboard/monitoring[21]
RightScale, unified cloud dashboard/monitoring
PaaS on IaaS
Makara, PaaS on IaaS[22]
rPath[23]
IT firms involved in cloud computing
Accenture
CA Technologies[24]
Cisco[25]
Citrix
Dell[26]
EMC[27]
Enterasys
Fujitsu
Hewlett Packard[28]
Hitachi
Huawei[29]
IBM[30]
Microsoft
NetApp
Red Hat[31]
VMware
Cloud storage technology providers
Microsoft SQL Azure
Gluster
Cloud Testing Providers
Qutesys[32]
QSIT[33]