Cloud computing refers to a model of network computing where applications and services run on remote servers accessed over the internet rather than local devices. It allows users to access computing resources like servers, storage, databases, networking, software and analytics from anywhere. Key characteristics include on-demand self-service, broad network access, resource pooling, rapid elasticity and measured service. Major cloud service models are software as a service (SaaS), platform as a service (PaaS) and infrastructure as a service (IaaS).

1. Cloud Computing
C.Kalpana

2. 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
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
time, utilizing the concept of virtualization.

3. 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.

4. 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.
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.”

5. 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

6. CLOUD COMPUTING

7. CLOUD COMPUTING
Cloud 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.

8. 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.

9. 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.

10. HISTORY OF CLOUD COMPUTING
It was a gradual evolution that started in the 1950s
with mainframe computing.

11. 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.

12. HISTORY OF CLOUD COMPUTING
After some time, around 1970, the concept of
virtual machines (VMs) was created.

13. 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.

15. 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.

16. 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.

17. Vision of cloud computing
A cloud is simply a centralised technology platform which provides specific IT
services to a selected range of users, offering the ability to login from anywhere,
ideally from any device and over any connection, including the Internet.

18. CLOUD COMPUTING is a model for enabling convenient, on demand
network access to a shared pool of configurable computing resources
(e.g., networks, servers, storage, applications and services) that can be
rapidly provisioned and released with minimal management effort or
service provider interaction
Definition according to National Institute
of Standards and Technology (NIST)
CLOUD
COMPUTING

19. NIST
 Note 1: Cloud computing is still an evolving paradigm. Its definitions,
use cases, underlying technologies, issues, risks, and benefits will be
refined in a spirited debate by the public and private sectors. These
definitions, attributes, and characteristics will evolve and change over
 Note 2: The cloud computing industry represents a large ecosystem of
many models, vendors,and market niches. This definition attempts to
encompass all of the various cloud approaches

20. DEFINITION OF CLOUD COMPUTING:
CLOUD COMPUTING is a model for enabling convenient,
demand network access to a shared pool of configurable
computing resources (e.g., networks, servers, storage,
applications, and services) that can be rapidly provisioned
and released with minimal management effort or service
provider interaction. this cloud model promotes availability
and is composed of five essential characteristics, three
service models, and four deployment models.

21. On-
demand
Self
Service
Broad
Network
Access
Resource
Pooling
- Location
Independence
Rapid
Elasticity
Measured
Service
5 ESSENTIAL CLOUD CHARACTERISTICS

22. on-demand self-service. a consumer can unilaterally
provision computing capabilities, such as server
and network storage, as needed automatically
without requiring human interaction with each
service’s provider.
BROAD NETWORK ACCESS. capabilities are
available over the network and accessed through
standard mechanisms that promote use by
heterogeneous thin or thick client platforms (e.g.,
mobile PHONES, LAPTOPS, AND PDAS).

23. Resource pooling. The provider’s computing
resources are pooled to serve multiple consumers
using a multi-tenant model, with different
physical and virtual resources dynamically
and reassigned according to consumer demand.
There is a sense of location independence in that
the customer generally has no control or
knowledge over the exact location of the provided
resources but may be able to specify location at a
higher level of abstraction (e.g., country, state, or
datacenter). Examples of resources include
processing, memory, network bandwidth, and
virtual machines.

24.  Rapid elasticity. Capabilities can be rapidly and
elastically provisioned, in some cases automatically, to
quickly scale out and rapidly released to quickly scale
in. To the consumer, the capabilities available for
provisioning often appear to be unlimited and can be
purchased in any quantity at any time.
 Measured Service. Cloud systems automatically
control and optimize resource use by leveraging a
metering capability at some level of abstraction
appropriate to the type of service (e.g., storage,
processing, bandwidth, and active user accounts).
Resource usage can be monitored, controlled, and
reported providing transparency for both the provider
and consumer of the utilized service.

25. 4 CLOUD DEPLOYMENT MODELS
Enterprise owned or leased
Shared infrastructure for specific community
Sold to public, mega-scale infrastructure
Composition of two or more clouds
FOUR DEPLOYMENT MODELS

26. SOFTWARE AS A SERVICE
(SAAS)
It is a Software Delivery Model
 Service is delivered through a browser.
 No Hardware or Software to manage.
 Increasingly popular with Small and Medium sized Enterprises (SME).
Examples of usage:
 Your email is hosted on an exchange server in your office and it is very slow. You
may outsource this with services like Hosted exchange.
 Your current Customer Relationship Management (CRM) package is not managing
the load or you simply don’t want to host it in-house. You may use SaaS provider
such as salesforce.com.
 Enterprise Fraud Management through SaaS.

27. » It is a Platform delivery model which deploys customer created applications to a cloud.
» Plat forms which are built upon Infrastructures are expensive, hence it is cost efficient to
go for platforms as a service.
» The Platform management is also cumbersome when compared to using a platform as a
service.
» Estimating the demand in a platform is highly unpredictable, hence the platform as a
service can take care of the demand.
» Examples of usage:
» You need to host a large file (10MB) on your website and making it available for 35,000 users for
only two months duration. You may use Cloud Front from amazon.
» You want to start Storage Services on your network for a large number of files and you do not
have the storage capacity. You may use Amazon S3.
Platform as a Service (PaaS)

28. ‼ It is a Computer Infrastructure delivery model. Hiring fundamental Computing
Resources.
‼ Access to
→ Infrastructure stack.
→ Full Operating System access.
→ Firewalls.
→ Routers.
→ Load Balancing.
‼ Example of usage:
→ You want to host a website but only for a few days. You may use Flexi Scale.
→ You want to run a batch job but you do not have the infrastructure necessary
to run it in a timely manner. You may use Amazon EC2.
INFRASTRUCTURE AS A SERVICE (IAAS)