"what's all this about the 'cloud' then"? she asked

"Whats all this about the cloud and cloud computing then?" she asked me when she finally thought it worth her time to actually be interested in what line of work I was into. Now I was in No-Man's land. 

I had to hit the fine balance of not boring her with the technical details and sounding too geeky, and yet I had to make sure I had her attention and interest by explaining the new and wonderful things the field of computer sciences has to offer to the world.

To begin with, Cloud Computing refers to the applications, platforms and infrastructure delivered as services over the Internet to the general public. These services themselves have long been referred to as Software as a Service (SaaS), plactform -as-a-service (PaaS) and Infrastructure-as-a-service (IaaS).

The datacenter hardware and software is what we will call a Cloud. When a Cloud and its services are made available in a pay-as-you-go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing.

We use the term Private Cloud to refer to internal datacenters and inter-connected IT resources of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS, Paas, Iaas and Utility Computing. People can be users or providers of SaaS, or users or providers of Utility Computing.

To make it simpler, Cloud computing is not so much a definition of a single term as a trend in service delivery taking place today. It’s the movement of application services onto the Internet and the increased use of the Internet to access a wide variety of services traditionally originating from within a company’s data center.

Reducing cost and enabling overall agility are the core attractions for businesses whilst reliability, security and privacy concerns are the main threats to users. Cloud computing has the potential for removing business friction to make more services possible and to do so much more easily, with less risk and capital outlay .

The essential characteristics of a successful cloud computing facility are: On-Demand Self Service, Broad Network Access, Resource Pooling, Rapid Elasticity or Rapid Scalability and Measurability of Service (Recommendations of NIST, Jan 2011)

To a newbie, this may take 2-3 days to begin to first understand and grasp the idea of Cloud Computing, and then the idea of Utility Computing as a service to the consumer.

But then if I had told her all of that, she would have thought I was a bit of a boaster and I would have effectively  bored her half to death. so I didn't tell her any of that. I kept it short and simple. This is what I told her.

"The idea is similar to a power station (datacenter) generating electricity (computing as a utility) to an assortment of electrical appliances (Applications) which are made use of by the consumer (End Consumer). The Consumer, by paying a nominal fee, will be able to utilize all the computing services provided by the cloud".  

"ohhh I see... that's very smart now :-)". she was interested.