In my last post, I tried to introduce you to the concept of “Cloud” and “Cloud Computing”.

Now let's examine what types of Clouds there are:

We basically have three types of Clouds: Public Clouds, Private Clouds and Hybrid Clouds.

To understand Cloud vocabulary, see this link.

Public Clouds :

These are the clouds which are open for use by general public and they exist beyond the firewall of an organization, fully hosted and managed by vendors like Google, Amazon, Microsoft, etc. They strictly follow “pay as you go” model which helps start ups to start small and go big without investing much in the IT infrastructure.

Here a user does not have a control on the management of the resources. Everything is managed by the third party and it’s their responsibility to apply software updates, security patches, etc .

They are quite effective and ease an organization's efforts as everything is already there.

They do face some criticism, especially on security related issues.

Private Clouds:

This is the type of Cloud which exists within the boundaries (firewall) of an organization. It is totally managed by an enterprise and has all the features of Public Clouds with a major difference that it has to take care the underlying IT infrastructure. They are more secure as they are internal to an organization and they shuffle resources according to their business needs.

They are best suited for the applications which are related to tight security and follows some stringent policies or are meant for regulatory purposes. It is not very easy for an organization to go with a Private Cloud due to its complexity and management so they are often used by enterprises who have made huge investments in their IT infrastructure and have the man power and abilities to manage it.

Hybrid Clouds:

These consist of external and internal providers, i.e. a mix of public and private clouds. Secure and critical apps are managed by an organization  and the not-so-critical and secure apps by the third party vendor. They have a unique identity bound by standard technology thus enabling data and application portability. They are used in the situations like Cloud Bursting (the dynamic deployment of a software application that runs on internal organizational computer resources to a public cloud to address a spike in demand).

In most countries, we are going to see lot of investment in the Hybrid Clouds in the next decade, for the simple reason, that lot of companies are skeptical about the Cloud’s Security and they prefer that the critical data be managed by themselves and the non-critical data by the external provider.

From an end-user perspective, Public Clouds will be more interesting.

We all use Public Cloud services like Microsoft Office Web apps, Windows Live Mesh 2011, Google Docs, etc.

An enterprise will have an interest in private & hybrid clouds. They would have an interest in exploring Microsoft Exchange online, Share Point online, and similar services for this.

Source: http://www.thewindowsclub.com/types-of-clouds-and-cloud-computing#ixzz1AhAvu2vz

Coming Articles: 1) Cloud Computing Part 3

                          2) MS Azure.