This document provides an overview of cloud computing, including its history, models, types, advantages and recent developments. Some key points: 1) Cloud computing originated from network diagrams depicting the internet as a cloud. Major companies like Amazon Web Services, Google, and IBM launched cloud services in the mid-2000s. 2) There are three main models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). IaaS provides basic storage and computing resources, while PaaS and SaaS provide higher-level services. 3) The four main types of cloud are public, community, hybrid, and private clouds

1. CLOUD COMPUTING
By Mr. Jagdeesha Kulal J
Contents
SL.NO TITLE
01. Meaning
02. Origins
03. History
04. Overview
05. Advantage of using public cloud
06. What does a shift towards cloud computing mean?
Characteristics
07.
Service models
08.
Types of cloud
09.
Cloud storage advantages
10.
Cloud computing and small business
11.
Recent developments
12.
Top10 companies
13.
Disadvantage of cloud computing
14.

2. Public Cloud
Meaning:
A public cloud is established where several organizations have similar requirements and seek to
share infrastructure so as to appliance. In addition, it can be economically attractive as the
resources (storage, workstations) utilized and shared in the community are already exploited.
This is the cloud computing model where service providers make their computing resources
available online for the public. It allows the users to access various important resources on
cloud, such as: Software, Applications or Stored data. One of the prime benefits of using public
cloud is that the users are emancipated from performing certain important tasks on their
computing machines that they cannot get away with otherwise, these include: Installation of
resources, their configuration; and Storage.
Origins:
Before cloud file sharing and collaboration software, most collaboration was limited to more
primitive and less effective methods such as email and FTP among others. These did not work
particularly well, and so the need emerged for a simple to use, yet feature rich cloud
collaboration solution.
Very early moves into cloud computing were made by Amazon Web Services who, in 2006,
began offering IT infrastructure services to businesses in the form of web service. Cloud
computing only began to come to real prominence in 2007 when Google decided to move parts
of its email service to a public cloud. It was not long before IBM and Microsoft followed suit with
Lotus Live and Business Productivity Online Standard Suite (BPOS) respectively. With an
increase in cloud computing services, cloud collaboration solutions were able to evolve. Since
2007, many new, innovative firms have entered the industry offering new features and a more
complete cloud collaboration system, filling ps in the market left by less adaptable large existing
software firms.
Many analysts explain the rise of cloud collaboration by pointing to the increasing use by
workers of non-authorized websites and online tools to do their jobs. This includes the use of
instant messaging and social networks. In a survey taken in early 2011, 22% of workers
admitted to having used one or more of these external non-authorized websites. Cloud
collaboration packages provide the ability to collaborate on documents together in real time,
making the use of non – authorized instant messaging redundant. IT managers can now
properly regulate internet based collaboration with a system tailor made for the
History:
The origin of the term cloud computing is obscure, but it appears to derive from the practice of
using drawings of stylized clouds to denote networks in diagrams of computing and

3. communications systems. The word cloud is used as a metaphor for the Internet, based on the
standardized use of a cloud-like shape to denote a network on telephony schematics and later
to depict the Internet in computer network diagrams as an abstraction of the underlying
infrastructure it represents. The cloud symbol was used to represent the Internet as early as
1994.
In the 1990s, telecommunications companies who previously offered primarily dedicated point-
to-point data circuits, began offering Virtual Private Network(VPN) services with comparable
quality of service but at a much lower cost. By switching traffic to balance utilization as they saw
fit, they were able to utilize their overall network bandwidth more effectively. The cloud symbol
was used to denote the demarcation point between that which was the responsibility of the
provider and that which was the responsibility of the users. Cloud computing extends this
boundary to cover servers as well as the network infrastructure.
Overview:
Cloud collaboration brings together new advances in cloud computing and collaboration that are
becoming more and more necessary in firms operating in an increasingly globalised world.
Cloud computing is a marketing term for technologies that provide software, data access, and
storage services that do not require end-user knowledge of the physical location and
configuration of the system that delivers the services. A parallel to this concept can be drawn
with the electricity grid, where end-users consume power without needing to understand the
component devices or infrastructure required to provide the service.
Collaboration, in this case, refers to the ability of workers in a company to work together
simultaneously on a particular task. In the past, most document collaboration would have to be
completed face to face. However, collaboration has become more complex, with the need to
work with people all over the world in real time on a variety of different types of documents,
using different devices. While growth in the collaboration sector is still growing rapidly, it has
been noted that the uptake of cloud collaboration services has reached a point where it is less
to do with the ability of current technology, and more to do with the reluctance of workers to
collaborate in this way. A report by Erica Regulates mapped out five reasons why workers are
reluctant to collaborate more. These are:
• People resist sharing their knowledge.
• Users are most comfortable using e-mail as their primary electronic collaboration tool.
• People do not have incentive to change their behavior.
• Teams that want to or are selected to use the software do not have strong team leaders
who push for more collaboration.
• Senior management is not actively involved in or does not support the team
collaboration initiative.
Advantages of using Public Cloud:

4. • Efficient storage and computing services
• Inexpensive, since all the virtual resources whether application, hardware or data are
covered by the the service provider.
• Allow for easy connectivity to servers and information sharing.
• Assures appropriate use of resources as the users are required to pay only for the
services they require.
• Highly reliable and redundant.
• Widespread availability irrespective of geographical precincts.
• Sets the business people free from the hassles of buying, managing and maintaining all
the virtual resources at their own end, the cloud server does it all.
• Public cloud, in today’s advanced workplace, empowers employees and enables them to
become productive even when outside the office. The SaaS model ensures that
corporations save on IT expenditures while delivering the flexibility of productivity
software on the cloud.
What does a shift towards cloud computing mean?
A paradigm shift to cloud computing will affect many different sub-categories in computer
industry such as software companies, internet service providers (ISPs) and hardware
manufacturers. While it is relatively easy to see how the main software and internet companies
will be affected by such a shift in Ginger's chunky nuggets, it is more difficult to predict how
companies in the internet and hardware sectors will be affected. Most of the major companies
have launched their product. IBM launched their new Smart Cloud data center in Japan in 2011.
Characteristics:
Agility improves with users' ability to re-provision technological infrastructure resources.
Application programming interface (API) accessibility to software that enables machines
to interact with cloud software in the same way the user interface facilitates interaction
between humans and computers. Cloud computing systems typically use REST-based
APIs.
Cost is claimed to be reduced and in a public cloud delivery model capital expenditure is
converted to operational expenditure. This is purported to lower barriers to entry, as
infrastructure is typically provided by a third-party and does not need to be purchased for
one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is
fine-grained with usage-based options and fewer IT skills are required for
implementation (in-house). The e-FISCAL project's state of the art repository contains
several articles looking into cost aspects in more detail, most of them concluding that
costs savings depend on the type of activities supported and the type of infrastructure
available in-house.
Device and location independence enable users to access systems using a web browser
regardless of their location or what device they are using (e.g., PC, mobile phone). As

5. infrastructure is off-site (typically provided by a third-party) and accessed via the
Internet, users can connect from anywhere.
Virtualization technology allows servers and storage devices to be shared and utilization
be increased. Applications can be easily migrated from one physical server to another.
Multitenancy enables sharing of resources and costs across a large pool of users thus
allowing for:
o Centralization of infrastructure in locations with lower costs (such as real estate,
electricity, etc.)
o Peak-load capacity increases (users need not engineer for highest possible load-
levels)
o Utilisation and efficiency improvements for systems that are often only 10–20%
utilised.
Reliability is improved if multiple redundant sites are used, which makes well-designed
cloud computing suitable for business continuity and disaster recovery.
Scalability and elasticity via dynamic ("on-demand") provisioning of resources on a fine-
grained, self-service basis near real-time, without users having to engineer for peak
loads.
Performance is monitored, and consistent and loosely coupled architectures are
constructed using web services as the system interface.
Security could improve due to centralization of data, increased security-focused
resources, etc., but concerns can persist about loss of control over certain sensitive
data, and the lack of security for stored kernels. Security is often as good as or better
than other traditional systems, in part because providers are able to devote resources to
solving security issues that many customers cannot afford. However, the complexity of
security is greatly increased when data is distributed over a wider area or greater
number of devices and in multi-tenant systems that are being shared by unrelated users.
In addition, user access to security audit logs may be difficult or impossible. Private
cloud installations are in part motivated by users' desire to retain control over the
infrastructure and avoid losing control of information security.
Maintenance of cloud computing applications is easier, because they do not need to be
installed on each user's computer and can be accessed from different places.
Service models
Cloud computing providers offer their services according to three fundamental models:
Infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service
(SaaS) where IaaS is the most basic and each higher model abstracts from the details of the
lower models
Infrastructure as a service (IaaS):
In this most basic cloud service model, cloud providers offer computers, as physical or more
often as virtual machines, and other resources. The virtual machines are run as guests by a
hypervisor, such as Xen or KVM. Management of pools of hypervisors by the cloud operational
support system leads to the ability to scale to support a large number of virtual machines. Other
resources in IaaS clouds include images in a virtual machine image library, raw (block) and file-
based storage, firewalls, load balancers, IP addresses, virtual local area networks (VLANs), and
software bundles. IaaS cloud providers supply these resources on demand from their large

6. pools installed in data centers. For wide area connectivity, the Internet can be used or in carrier
clouds dedicated virtual private networks can be configured.
To deploy their applications, cloud users then install operating system images on the machines
as well as their application software. In this model, it is the cloud user who is responsible for
patching and maintaining the operating systems and application software. Cloud providers
typically bill IaaS services on a utility computing basis, that is, cost will reflect the amount of
resources allocated and consumed.
IaaS refers not to a machine that does all the work, but simply to a facility given to businesses
that offers users the leverage of extra storage space in servers and data centers.
Examples: Amazon Cloud Formation (and underlying services such as Amazon EC2), Rack
space Cloud, Google Engine and Right Scale.
Platform as a service (PaaS):
In the PaaS model, cloud providers deliver a computing platform typically including operating
system, programming language execution environment, database, and web server. Application
developers can develop and run their software solutions on a cloud platform without the cost
and complexity of buying and managing the underlying hardware and software layers. With
some PaaS offers, the underlying computer and storage resources scale automatically to match
application demand such that cloud user does not have to allocate resources manually.
Examples: Amazon Elastic Beanstalk, Heroku, Engine Yard, Mendix, Google App Engine,
Microsoft Azure and Orange Scape.
Software as a service (SaaS):
In this model, cloud providers install and operate application software in the cloud and cloud
users access the software from cloud clients. The cloud users do not manage the cloud
infrastructure and platform on which the application is running. This eliminates the need to
install and run the application on the cloud user's own computers simplifying maintenance and
support. What makes a cloud application different from other applications is its elasticity. This
can be achieved by cloning tasks onto multiple virtual machines at run-time to meet the
changing work demand. Load balancers distribute the work over the set of virtual machines.
This process is inconspicuous to the cloud user who sees only a single access point. To
accommodate a large number of cloud users, cloud applications can be multitenant, that is, any
machine serves more than one cloud user organization. It is common to refer to special types of
cloud based application software with a similar naming convention: desktop as a service,
business process as a service, test environment as a service, communication as a service.
The pricing model for SaaS applications is typically a monthly or yearly flat fee per user.
Examples: Google Apps, Quickbooks Online, Salesforce.com and Microsoft Office 365.
Types of cloud:

7. Public cloud: Public cloud applications, storage, and other resources are made available to the
general public by a service provider. These services are free or offered on a pay-per-use model.
Generally, public cloud service providers like Amazon AWS, Microsoft and Google own and
operate the infrastructure and offer access only via Internet (direct connectivity is not offered).
Community cloud: Community cloud shares infrastructure between several organizations from
a specific community with common concerns (security, compliance, jurisdiction, etc.), whether
managed internally or by a third-party and hosted internally or externally. The costs are spread
over fewer users than a public cloud (but more than a private cloud), so only some of the cost
savings potential of cloud computing are realized.
Hybrid cloud: Hybrid cloud is a composition of two or more clouds (private, community or
public) that remain unique entities but are bound together, offering the benefits of multiple
deployment models.
By utilizing "hybrid cloud" architecture, companies and individuals are able to obtain degrees of
fault tolerance combined with locally immediate usability without dependency on internet
connectivity. Hybrid Cloud architecture requires both on-premises resources and off-site
(remote) server based cloud infrastructure.
Hybrid clouds lack the flexibility, security and certainty of in-house applications. Hybrid cloud
provides the flexibility of in house applications with the fault tolerance and scalability of cloud
based services.
Private cloud: Private cloud is cloud infrastructure operated solely for a single organization,
whether managed internally or by a third-party and hosted internally or externally. Undertaking a
private cloud project requires a significant level and degree of engagement to virtualize the
business environment, and it will require the organization to reevaluate decisions about existing
resources. When it is done right, it can have a positive impact on a business, but every one of
the steps in the project raises security issues that must be addressed in order to avoid serious
vulnerabilities.
They have attracted criticism because users "still have to buy, build, and manage them" and
thus do not benefit from less hands-on management, essentially "[lacking] the economic model
that makes cloud computing such an intriguing concept".
Cloud storage advantages:
• Companies need only pay for the storage they actually use as it is also possible for
companies by utilizing actual virtual storage features like thin provisioning.
• Companies do not need to install physical storage devices in their own datacenter or
offices, but the fact that storage has to be placed anywhere stays the same (maybe
localization costs are lower in offshore locations).
• Storage maintenance tasks, such as backup, data replication, and purchasing additional
storage devices are offloaded to the responsibility of a service provider, allowing
organizations to focus on their core business, but the fact stays the same that someone
has to pay for the administrative effort for these tasks

8. • Cloud storage provides users with immediate access to a broad range of resources and
applications hosted in the infrastructure of another organization via a web service
interface.
Cloud storage can be used for copying virtual machine images from the cloud to on-premise
locations or to import a virtual machine image from an on-premise location to the cloud image
library. In addition, cloud storage can be used to move virtual machine images between user
accounts or between data centers
Cloud Computing and Small Business:
For a small and medium size business (SMB), the benefits of cloud computing is currently
driving adoption. In the SMB sector there is often a lack of time and financial resources to
purchase, deploy and maintain an infrastructure (e.g. the software, server and storage).
In cloud computing, small businesses can access these resources and expand or shrink
services as business needs change. The common pay-as-you-go subscription model is
designed to let SMBs easily add or remove services and you typically will only pay for what you
do use.
Recent developments:
• Recently, cloud collaboration has seen rapid evolution. In the past, cloud collaboration
tools have been quite basic with very limited features. Newer, packages are now much
more document-centric in their approach to collaboration. More sophisticated tools allow
users to "tag" specific areas of a document for comments which are delivered real time
to those viewing the document. In some cases, the collaboration software can even be
integrated into Microsoft Office, or allow users to set up video conferences.
• Furthermore, the trend now is for firms to employ a single software tool to solve all their
collaboration needs, rather than having to rely on multiple different techniques. Single
cloud collaboration providers are now replacing a complicated tangle of instant
messengers, email and FTP.
• Cloud collaboration today is promoted as a tool for collaboration internally between
different departments within a firm, but also externally as a means for sharing
documents with end-clients as receiving feedback. This makes cloud computing a very
versatile tool for firms with many different applications in a business environment.
• A 2011 report by Gartner outlines a five stage model on the maturity of firms when it
comes to the uptake of cloud collaboration tools. A firm in the first stage is said to be
"reactive", with only email as a collaboration platform and a culture which resists
information sharing. A firm in the fifth stage is called "pervasive", and has universal
access to a rich collaboration toolset and a strong collaborative culture. The article
argues that most firms are in the second stage, but as cloud collaboration becomes

9. more important, most analysts expect to see the majority of firms moving up in the
model.
Top 10 companies:
10.Vm ware
9. Microsoft
8. Bluelock
7. Citrix
6. Joyent
5. Verizon/Terremark
4. Salesforce.com
3. CenturyLink/Savvis
2. Rackspace
1.Amazon Web Services
Disadvantages of Cloud Computing:
• Possible downtime: Cloud computing makes your small business dependent on the
reliability of your Internet connection. When it's offline, you're offline. And even the most
reliable cloud computing service providers suffer server outages now and again.
• Security issues: How safe is your data? Cloud computing means Internet computing.
So you should not be using cloud computing applications that involve using or storing
data that you are not comfortable having on the Internet. That being said, established,
reliable cloud computing vendors will have the latest, most sophisticated data security
systems possible as they want your business and realize that data security is a big
concern.
Switching to the cloud can actually improve security for a small business, says Michael
Redding, managing director of Accenture Technology Labs. "Because large cloud
computing companies have more resources, he says, they are often able to offer levels
of security an average small business may not be able to afford implementing on its own
servers"
• Cost: At first glance, a cloud computing application may appear to be a lot cheaper than
a particular software solution installed and run in-house, but you need to be sure you're
comparing apples and apples. Does the cloud application have all the features that the
software does and if not, are the missing features important to you?
You also need to be sure you are doing a total cost comparison. While many cloud
computer vendors present themselves as utility-based providers, claiming that you're

10. only charged for what you use, Gartner says that this isn't true; in most cases, a
company must commit to a predetermined contract independent of actual use. To be
sure you're saving money, you have to look closely at the pricing plans and details for
each application.
• Inflexibility: Be careful when you're choosing a cloud computing vendor that you're not
locking your business into using their proprietary applications or formats. You can't insert
a document created in another application into a Google Docs spreadsheet, for instance.
Also make sure that you can add and subtract cloud computing users as necessary as
your business grows or contracts.
• Lack of support: In These Issues Need to be Resolved Before Cloud Computing
Becomes Ubiquitous, (OPEN Forum) Anita Campbell writes, "Customer service for Web
apps leaves a lot to be desired -- All too many cloud-based apps make it difficult to get
customer service promptly – or at all. Sending an email and hoping for a response within
48 hours is not an acceptable way for most of us to run a business".