Cloud computing is a phrase used to describe a variety of computing concepts that involve a large number of computers connected through a real-time communication network such as the Internet.[1] In science, cloud computing is a synonym for distributed computing over a network, and means the ability to run a program or application on many connected computers at the same time. The phrase also more commonly refers to network-based services, which appear to be provided by real server hardware, and are in fact served up by virtual hardware, simulated by software running on one or more real machines. Such virtual servers do not physically exist and can therefore be moved around and scaled up (or down) on the fly without affecting the end user - arguably, rather like a cloud.

2. CONTENTS
 Introduction
 Functionality of cloud computing
 Technologies used in cloud computing
 Cloud services
 Advantages and disadvantages
 Conclusion

3. What is Cloud Computing?
 Cloud computing, often referred to as simply “the cloud,”
is the delivery of on-demand computing resources—
everything from applications to data centers—over the
Internet and on a pay-for-use basis.
 Cloud computing is a type of computing that relies
on sharing computing resources rather than having local
servers or personal devices to handle applications.

4. Functionality of cloud computing
 Cloud Computing is a general term used to describe a
new class of network based computing that takes place
over the Internet
 In addition, the platform provides on demand services,
that are always on, anywhere, anytime and any place.
 Pay for use and as needed, elastic, scales up and down in
capacity and functionalities
 The hardware and software services are available to
general ,public, enterprises, businesses markets

5. Technologies used in Cloud
Computing
• Physical
• Servers
• Load Balancer
• Data center network
• Virtual
• Operating System
• Security Software
• Applications

6. Cloud Service Models

7. Library Services using Cloud
Worldcat
Mendeley
ExLibris
Research Gate
Google Scholar
Library
Thing
Dropbox

8. Infrastructure as a service (IaaS):
 Offer computer’s physical or virtual machines and other
resources.
 Support large numbers of virtual machines
 Offers virtual-machine disk image library, raw
(block) and file-based storage, firewalls, load balancers,
IP addresses, virtual local area networks (VLANS).
 Supply these resources on-demand from their large
pools installed in data centres

9. Platform as a Service (PaaS):
 delivers a computing platform, typically including
operating system, programming language execution
environment, database, and web server.
 Useful service for Application Developers
 Run and Develop the software without the cost and
complexity of buying and managing the underlying
hardware and software layers.

10. Software as a Service:
 Provides access to application software and databases
 Manages the infrastructure and platforms that run the
applications.
 Provides install and operate application software on
cloud.
 Also known as "Software on Demand"

11. Real World Examples
Real World Examples

12. Advantages of Cloud Computing
• Cost saving: You pay for only what you use.
• Easy on installation and maintenance.
• Increased storage.
• Highly automated.
• Flexibility.
• Better mobility.
• Shared resources.
• Back up and restoration.

13. Disadvantages of Cloud Computing
• Network connectivity and bandwidth.
• Service unavailability due to power outage.
• As per requirements updates are needed for client
machine.
• Does not work well with low speed connection.
• Data security.
• Privacy.

14. Conclusion
 Cloud Computing is in a period of strong growth,
but this technology is still has some issues of
security and somewhat it is immature.
 The real value of cloud computing is that it makes
your library related software and data available
transparently and everywhere including in latest
available smart phone devices.

15. References
 http://en.wikipedia.org/wiki/Cloud_computing
 http://drive.google.com
 http://skydrive.live.com
 http://www.dropbox.com