• Cloud is just a metaphor for the internet, when we say cloud, we are just referring to internet.
• In the simplest terms, cloud computing means storing and accessing data and programs over the Internet instead of our local computer’s hard drive.

• The phrase cloud computing means “a type of Internet-based computing” where different services — such as servers, storage and applications — are delivered to an organization’s computers and devices through the Internet.
• Cloud Computing refer to a variety of services available over the Internet that deliver computing functionality on the service provider’s infrastructure.
• A cloud computing service consists of highly optimized data centers (third party data centers from the end user point of view), that provide various hardware, software and information resources (when needed).
• Cloud platform hide the complexity and details of the underlying infrastructure from users and applications by providing very simple graphical interface or API (Applications Programming Interface).
• The Cloud platform provides on demand services that are always on, anywhere, anytime and anyplace.

Why are businesses moving to cloud?

In traditional hosting, a software company has to deal with licensing costs, protection of data, frequent upgrades to latest technologies, maintenance and up gradation of hardware and most important finding the right skillsets at the right time.

Cloud Characteristics

Characteristics of Cloud computing that distinguish it from traditional hosting.

• Remotely hosted: Services or data are hosted on remote infrastructure.
• Ubiquitous: Services or data are available from anywhere through internet.
• Resiliency: Cloud providers generally mirrors solutions to multiple data centers to minimize downtime in the event of a disaster.
• On-demand self-service: A consumer can himself provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider. It is sold on demand mostly by the minutes or hours. (Pay as you go model)
• Rapid elasticity – A user can utilize as much or little of the cloud service as required. For example resources (ex: webservers) on the cloud can be scaled to meet high traffic in peak times or scaled down in times of less traffic.
• Broad network access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
• Fully managed by the provider – The user is abstracted from the details of how the service is managed in the cloud. For example the user need not worry about aspects such as hardware used, software updates and patches, plug-ins, web security. There is optimum utilization of resources and as well as sharing of resources. Everything is taken care of by the provider.