What is cloud computing?

Cloud computing is self contained a model of computer networks for providing convenient but cost effective, on-demand network access to a shared pool of customizable computing resources (eg, networks, storage, servers, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.


Essential Attributes of Cloud Computing



Service Models


Software as a Service SaaS

Accessing applications running in Cloud, hosted to serve a large volume and users don 't have to worry about the application maintenance nor server hosting(Google Apps, SalesForce)

Platform as a Service PaaS

Deployment customer owned application in cloud, and the infra can be grown/shriken as per the demand.

Infrastructure as a Service

Rent processing, storage, network capacity, and other fundamental computing resources


Cloud Deployment Models


Private Cloud

In this the infrastructure will be dedicated for an organization.. It may be managed by the organization or a third party and may exist on premise or off premise

Community cloud

The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.

Public cloud

This infrastructure is made readily available to the public and have very large amount of resources connected and is owned by an organization selling cloud services.

Hybrid cloud

The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting).


Typical costs of downtime per employee, per hour, for ...


Source: APC Currents Magazine, August, 2010