What is Cloud
A model for delivering information technology services in which resources
are retrieved from the internet through web-based tools and applications,
rather than a direct connection to a server. Data and software packages
are stored in servers. However, cloud computing structure allows access to
information as long as an electronic device has access to the web. This
type of system allows employees to work remotely.
Software as a Service (SaaS)-End Users
Infrastructure as a Service (IaaS)-Application Developers
Platform as a Service (PaaS)- Network Architects
Application provided by
Why would anyone want to rely on another computer system to run
programs and store data?
The applications of cloud computing are practically limitless. With the right middleware, a cloud
computing system could execute all the programs a normal computer could run. Potentially,
everything from generic word processing software to customized computer programs designed for a
specific company could work on a cloud computing system.
Here are just a few reasons:
1. Clients would be able to access their applications and data from anywhere at any time. They
could access the cloud computing system using any computer linked to the Internet. Data
wouldn't be confined to a hard drive on one user's computer or even a corporation's internal
2. Servers and digital storage devices take up space. Some companies rent physical space to store
servers and databases because they don't have it available on site. Cloud computing gives these
companies the option of storing data on someone else's hardware, removing the need for
physical space on the front end. Corporations might save money on IT support. Streamlined
hardware would, in theory, have fewer problems than a network of heterogeneous machines and
Software as a Service-
Also known as On-demand Service.
Is an application that can be accessed from anywhere on the world as long as
you can have an computer with an Internet Connection.
We can access this cloud hosted application without any additional hardware
E.g. : G-mail, Yahoo mail, Hotmail etc..,
Also they can provide security features such as SSL encryption, a
Platform as a Service
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.
With some PaaS offers, the underlying computer and storage resources scale
automatically to match application demand so that the cloud user does not
have to allocate resources manually.
The latter has also been proposed by an architecture aiming to facilitate real-
time in cloud environments.
E.g.: Salesforce.com, Windows Azure etc.
Infrastructure as a
Also known as hardware as a service.
Is a computing power that you can rent for a limited period of time.
Allows existing applications to be run on a cloud suppliers hardware.
Cloud providers offer computers – as physical or more often as virtual
machines –, raw (block) storage, firewalls, load balancers, and networks
Modes of Clouds
• Computing infrastructure is hosted by cloud vendor at the vendors premises.
• and can be shared by various organizations.
• E.g. : Amazon, Google, Microsoft, Sales force
• The computing infrastructure is dedicated to a particular organization and not shared
with other organizations.
• more expensive and more secure when compare to public cloud.
• E.g. : HP data center, IBM, Sun, Oracle, 3tera
• Organizations may host critical applications on private clouds.
• where as relatively less security concerns on public cloud.
• usage of both public and private together is called hybrid cloud.
Cloud Operating Systems
iSpaces Cloud Computer
The Places A
Cloudo, Ghost, Zimdesk, Start force etc.,
Distributed vs. Grid vs. Cloud
Rent based on usage
Rent Servers & Hosting
costs whether used or
Buy Servers & Colo
costs whether used or
High - virtualizedLowLow“Green”
No contracts, usage
based, no upfront costs
Instant, Flexible, Pay-
Slowest, Rigid & CostlyScalability
MinutesDays to WeeksWeeks to MonthsTime
Is Cloud Computing reduces E-
Green IT Cloud Computing
Cloud Computing is Eco-Friendly.
We can reduce E-waste by using Cloud Computing i.e. by
Infrastructure as a Service (IaaS).
Cloud Computing Helps to Accelerate Green IT
Can reduce Global Warming too..
Disadvantages of Cloud
Security and privacy in the Cloud
Dependency and vendor lock-in
Technical Difficulties and Downtime
Limited control and flexibility
Cloud computing remains strong and has great potential for the future. Its user
base grows constantly and more big players are attracted to it, offering better
and more fine tuned services and solutions. We can only hope that the
advantages will further grow and the disadvantages will be mitigated, since cloud
computing seems to have made IT a little bit easier. Happy cloud computing!