Cloud computing allows users to access shared computing resources over the network. It maximizes resource use by dynamically allocating resources across users and locations. Cloud services include Software as a Service (SaaS), Infrastructure as a Service (IaaS), and Platform as a Service (PaaS). While the term cloud computing has been used since the 1960s, it is still evolving today to provide on-demand access to computing resources and data from anywhere.

1. Cloud Computing
By: Vaneesh Bahl

2. Introduction
Cloud computing is a model for enabling ubiquitous network access to a shared pool of
configurable computing resources. Cloud computing and storage solutions provide users
and enterprises with various capabilities to store and process their data in third-party data
centres. It relies on sharing of resources to achieve coherence and economies of scale,
similar to a utility (like the electricity grid) over a network. At the foundation of cloud
computing is the broader concept of converged infrastructure and shared services.
Converged infrastructure operates by
grouping multiple information
technology (IT) components into a single,
optimized computing package.
Components of a converged infrastructure
may include servers, data storage
devices, networking
equipment and software for
IT infrastructure management,
automation and orchestration.
Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the
effectiveness of the shared resources. Cloud resources are usually not only shared by
multiple users but are also dynamically reallocated per demand. This can work for allocating
resources to users. For example, a cloud computer facility that serves European users during
European business hours with a specific application (e.g., email) may reallocate the same
resources to serve North American users during North America's business hours with a
different application (e.g., a web server). This approach helps maximize the use of
computing power while reducing the overall cost of resources by using less power, air
conditioning, rack space, etc. to maintain the system. With cloud computing, multiple users
can access a single server to retrieve and update their data without purchasing licenses for
different applications.

3. History of Cloud Computing
The origin of the term cloud computing is unclear. The expression cloud is commonly used in
science to describe a large agglomeration of objects that visually appear from a distance as a
cloud and describes any set of things whose details are not inspected further in a given
context. It wouldn’t be justified to credit any one major company for inventing the cloud
services. Let’s take the example of one of the oldest and most popular cloud computing
services – the Teller machines (popularly known as the ATMs).
In the image on the left, we can see Actor Reg Varney using
the world's first cash machine in Enfield Town, north London
on 27 June 1967.
The first modern ATM was an IBM 2984 and came into use at
Lloyds Bank, England in December 1972.
ATMs certainly qualify as a cloud computing service where
the end user can withdraw cash wirelessly anywhere in the
world.

4. Another widely used cloud computing service that has been
in existence for more than 3 decades now is Email. We have
been unknowingly using Emails as a cloud service since 1980s.
Earlier we used to go to the internet cafes to access our
emails and with increasing development in technology, the
day has come where we just have to unlock our smart phone and send/receive email from
any part of the world. That’s the power of the cloud!
"Who invented cloud computing? Some say it was
Amazon.com in 2006. Others say it was Google a few years
earlier. But it's all a matter of perspective. There is no
definite answer to this but there is an indirect reference to
one of the world’s biggest telecommunication companies
using this word in 1994. That was AT&T, while talking about
its software platform called TeleScript.
In other words, "the cloud" has been around for a long time as a buzzword, well before it
appears to take on a life of its own in 2006, give or take a year. The fact of the matter is the
term has evolved over time, and it is still evolving. The concept of "the cloud" is and was far
different from its meaning in the 1960s, 1970s, 1980s, and 1990s than today.
Characteristics of a Cloud Computing Service:
 Remotely hosted: Services or data are
hosted on remote infrastructure.
 Ubiquitous: Services or data are available
from anywhere.
 Commoditised: The result is a utility
computing model similar to traditional that of
traditional utilities, like gas and electricity -
you pay for what you would want!
 Elastic: Scale up or down quickly and
easily to meet demand.

5. Flavours of Cloud services:
 SaaS – Software as a Service
 IaaS – Infrastructure as a Service
 PaaS – Platform as a Service
Software as a Service (SaaS)
Software as a Service is a model in which an application is hosted as a service to the
customers who access via the Internet. When the software is hosted offsite, the customer
doesn’t have to maintain it or support it. On the other hand, it is out of the customer’s
hands when the hosting service decides to change it. The idea is to use the software out of
the box as is and do not need to make a lot of changes or require integration to other
systems. The service provider does all the patching and upgrades as well as keeping the
infrastructure running.
Examples:
 Customer Resource Management (CRM)
Like salesforce.com which provides a full customer relationship management (CRM).
 Google Apps: provides web-based office tools such as e-mail, calendar, and
document management
 Video Conferencing
 Accounting

6. Platform as a Service (Paas)
PaaS supplies all the resources required to build applications and services completely from
the internet, without having to download or install any software. Essentially in PaaS,
application development platforms allow users to leverage the resources of established
organizations to create and host applications of a larger scale than an individual or small
business would be able to handle.
Examples:
 Google App Engine: provides users with a complete development stack and allows
them to run their applications on Google’s infrastructure
 Microsoft Azure Services Platform: provides users with a development platform
based on Windows Azure
(Above picture represents the various service types with the extent of involvement)
Infrastructure as a Service (IaaS)
This capability type provides mainly computational infrastructure available over the internet
(e.g., compute cycles or storage). IaaS allows organizations and developers to extend their IT
infrastructure on an on-demand basis. It simply offers the hardware so that an organization
can put whatever they want onto it.

7. IaaS model allows a service provider to rent out services like:
 Server Space
 Network Equipment
 Memory
 CPU Cycles
 Storage Space
Examples:
 Amazon Elastic Compute Cloud (EC2): provides users with a special virtual machine
(AMI) that can be deployed and run on the EC2 infra-structure
 IBM Computing on Demand (CoD): provides users with access to high-ly configurable
servers plus value-added services such as data storage
 Rackspace Cloud: provides users with access to dynamically scalable computing and
storage resources, as well as third-party cloud applica-tions and tools
Cloud Deployment Models
There are different types of clouds that you can subscribe to depending on your needs. As a
home user or small business owner, you will most likely use public cloud services.
 Public Cloud - A public cloud can be accessed
by any subscriber with an internet
connection and access to the cloud
space.
 Private Cloud - A private cloud is
established for a specific group or
organization and limits access to just
that group.
 Hybrid Cloud - A hybrid cloud is
essentially a combination of at least two
clouds, where the clouds included are a
mixture of public, private, or community.
 Community Cloud - A community cloud
is shared among two or more
organizations that have similar cloud requirements.

8. Comparison of the Cloud deployment models:
Public Cloud Private Cloud Hybrid Cloud Community Cloud
In Public cloud the
computing
infrastructure is
hosted by the
cloud vendor at
the vendor
premises.
The customer has
no visibility and
control over where
the computing
infrastructure is
hosted.
The computing
infrastructure is
shared between
any organizations.
The computing
infrastructure is
dedicated to a particular
organization and NOT
shared with other
organizations.
Private clouds are more
expensive and more
secure when compared
to public clouds.
Private clouds are of
two types: On-premise
private clouds and
externally hosted
private clouds.
Externally hosted
private clouds are
cheaper than On-
premise private clouds.
Organizations may host
critical applications on
private clouds and
applications with
relatively less security
concerns on the public
cloud. The usage of both
private and public clouds
together is called hybrid
cloud.
A related term is Cloud
Bursting. In Cloud
bursting organization use
their own computing
infrastructure for normal
usage, but access the
cloud using services
like Salesforce cloud
computing for high/peak
load requirements.
This ensures that a
sudden increase in
computing requirement is
handled gracefully.
Community
cloud involves sharing
of computing
infrastructure in
between organizations
of the same
community.
For example all
Government
organizations within
the state of California
may share computing
infrastructure on the
cloud to manage data
related to citizens
residing in California.

9. Future of Cloud Computing
A lot has been written or spoken about in regards to cloud computing market and its
growth over the last few years. The subject has become an enigma and can be seen to
perplex even those most technically minded individuals.
Growing technological developments such as disaster recovery are also pivotal to the future
of cloud computing. Report by RapidScale suggested that 43% of companies that experience
a disaster never reopen, which has led to more than 50% of ‘cloud using organization’
transferring their most precious material to secure, isolated data centres.
In a recent presentation based on the report, titled State of the Cloud Computing 2015, from
Bessemer Venture Partners’s Byron Deeter showed that the cloud computing market is
growing at a 22.8% compound annual growth rate, and will reach $127.5 billion in 2018. There
are now 28 private cloud $1.5 billion+ business’, with market leaders Dropbox being valued
at an estimated $15 billion. The report also claims that by 2018, 62% of all CRM software will be
cloud-based; Salesforce will leverage on cloud the most and strengthen its market leader
position. 30% of all application spending is for SaaS-based applications, projected to grow at a
CAGR of 17.6% from 2013 to 2018.
Cloud Computing has already started
shaping our future in ways known and
unknown to us.
With so many advancements in digital
technologies, computing will certainly
not be the same for the upcoming
generations.
And there is no denial in saying -
The Future is NOW!!!