CLOUD COMPUTING

Definition:

Cloud computing is Internet-based computing, whereby shared resources, software, and information are provided to computers and other devices on demand, like the electricity grid.

Concept:

Let’s try to understand cloud computing with the help of an example. Consider a large organization having large number of employees. Suppose that for each of these employees, the organization will provide a desktop at workplace consisting of the required hardware and software. The company will have to purchase the requisite software licenses, requiring huge investments. Now consider that there is a server that hosts all the required applications and softwares. All the employees of the company can then log on to this web – based service and access applications required to perform his or her job. The server, or the remote machines owned by another company would run everything from e-mail to word processing to complex data analysis programs. This is what cloud computing is basically all about.

Applications:

Many forms of cloud computing may already be used in our day-to-day lives. If you have an e-mail account with a Web-based e-mail service like Hotmail, Yahoo! Mail or Gmail, then you've had some experience with cloud computing. Instead of running an e-mail program on your computer, you log in to a Web e-mail account remotely. The software and storage for your account doesn't exist on your computer -- it's on the service's computer cloud. Similarly, usage of google docs provided by Google can be considered as an application of Cloud computing.

Cloud Computing Types:

Saas: It stands for software as a service. As the name suggests, software applications are provided as a service to the customer. Applications are hosted by the provider and will be accessible to the customer via the web.
Example: Google Apps, Sales Force (CRM)

Iaas: Computer infrastructure as a service called as ‘Infrastructure as a service’ ,can be provided to the customer via the web.
Example: Amazon web services, Rackspace cloud.

Paas: ‘Platform as a service’ such as the Operating System is also a variant of cloud computing.
Example: Microsoft Azure, Google App Engine

Advantages:

The company can focus on its core competency rather than focusing on managing the required hardware and software infrastructure.
All the processing will take place at the remote machines or server provided by the service provider thus saving a lot of processing power on the local machines.
Cloud computing generally works on the concept of pay-per-use. The service provider will charge the customer on the basis of number of applications used and the time period for which the service is used. This can be beneficial especially for smaller organizations who cannot bear costs of having their own hardware or software infrastructure.
Cloud computing can provide a lot of flexibility in a way that you do not get tied up with a particular hardware or software. The customer can subscribe to a given service for specified period of time after which he may discontinue the service if required.