| Cloud Computing? Sounds a bit uncanny! Right! Well, | | | | The SaaS model is one where both software and |
| what it does on the first instant is send in images of | | | | hardware infrastructure is made available by the |
| cloud before your mind's eye and your confusion | | | | service provider and he communicates with user via a |
| seems to build up more and more. | | | | frontend portal. Services like inventory control, web |
| However, before any more is dwelt on the concept | | | | mail, data processing etc can be accessed on a SaaS |
| of Cloud technology, let's know how the term gained | | | | model of cloud. |
| currency. It is common for programmers and | | | | The PaaS model of Cloud is one in which product |
| software architects to use the symbol or image of a | | | | development utilities and set of software are hosted |
| cloud in their diagrams and flowcharts while referring | | | | on service provider's infrastructure. Users create and |
| to Internet- hence the name Cloud computing came | | | | produce applications directly on the provider's |
| into being. So whenever hosted services are provided | | | | platform over the web. Notable and well-known |
| over the web, what you get to call it is cloud-based | | | | examples of PaaS are Google Apps and |
| computing. | | | | Infrastructure-as-a-Service or IaaS is a cloud model |
| The other question you may ask is how it differs | | | | that offers virtual server instances with blocks of |
| from conventional web hosting. In fact the difference | | | | storage on demand and unique IP addresses. The |
| lies in the fact thata) a cloud service is always a | | | | virtual servers and storage are accessed, stopped |
| totally managed hosting solution by the service | | | | and configured by subscribers using the API |
| provider,b) it is an on-demand service and exists in | | | | (application program interface) of the service |
| slots of minutes or hours,c) it is flexible in that you | | | | provider. A good example of IaaS is the Amazon |
| can take as much as you need just like your gasoline. | | | | Web Services. The Amazon model is also known as |
| With technological advances and greater web | | | | an instance of Public Cloud. In Public cloud, services |
| connectivity and need to cut down IT operational | | | | can be purchase by anyone on the web while in |
| costs, industry experts have seen tremendous burst | | | | contrast Private Cloud makes available hosted |
| in adoption of cloud computing service. | | | | services to a restricted and pre-defined network of |
| Cloud services can be classified in three broad | | | | people. However, the key idea and focus in Cloud |
| groups,a) Software-as-a-Service (SaaS),b) | | | | computing is to render elastic, scalable and |
| Platform-as-a-Service (PaaS), &c) | | | | on-demand computing resources to users globally. |
| Infrastructure-as-a-Service. | | | | |