1. What is Cloud Computing?
  2. Definition of Cloud Computing
  3. Advantages & limitations of Cloud Computing

What is Cloud Computing?

Situation 1

  • I am looking for a house. My first constraint, being a middle class man, obviously is money. The House owner here is ready to give his house on rent to me. But demands more than my budget. And this is a house which can accommodate more than 4 persons. Now we both came to a deal:
  • I shall share the house with 3 other persons.
  • They shall share the rent.
  • Now the deal is both economical and efficient in the usage of the living space.

Situation 2

  • I want a cycle, I want it to be the latest, the best, but only for a month. Here came the cycle salesman. He gave me a fair deal, a decently modern cycle which I can own for myself just for 1 month after which I have to give him back his cycle with usage charge for his service.
  • These transactions are pretty common in our daily life. Do you understand these? Then you have understood CLOUD COMPUTING only thing, replace the house and the cycle with hardware and software.

Definition of Cloud Computing

  • Cloud Computing provides the infrastructures (both software and hardware) as services on a semi –permanent (rented) basis
  • you don’t add physical assets (server computers, Air conditioners, special IT staff to maintain those server rooms etc.)
  • instead you are provided with great flexibility and choice in your purchase is known as Cloud computing.

Based on different computing resources, services include

Type Purpose Provider(Eg)
Infrastructure as a service (IaaS) Entire systems (virtual machines) will be provided to the users. Users can access the systems through internetService providers charge based on the resource allocated Amazon
Platform as a service (PaaS) In this model entire system along with the operating systems, software is provided. Google App Engine
Software as a service (SaaS) This one is more commonSoftware created by service provider.
End users use these services on a subscription basis
Yahoo, Gmail
Storage as a service (STaaS) Storage is provided getting rid of maintaining separate storage devices. Windows Skydrive

Pros and Cons of Cloud Computing


  • No responsibility of creation, maintenance of systems.
  • Easy implementation and economical.
  • Flexibility in hardware and software i.e., pay as you use.
  • Easy up-gradation to match current technology.
  • Efficient usage of resources.
  • Location independence i.e., accessible from anywhere.


  • Data security.
  • Need for high speed internet connection (Essentially a big constraint for a country like ours).
  • Universal standardization required which makes interoperability among providers difficult as of now.
  • Dependent on service providers even for trivial applications.

This was a guest post by Manikandan.