What is Cloud Computing

The concept of Accessing a Software Application or a Platform or an Infrastructure over the internet instead of using them by purchasing and installing is called Cloud Computing.

GENERALLY THERE ARE THREE LAYERS OF CLOUD COMPUTING

• IAAS(Infrastructure as a Service)
• PAAS(Platform as a Service)
• SAAS(Software as a Service)

IAAS(INFRASTRUCTURE AS A SERVICE) :

If an Infrastructure such as Storage server or an Application Server is accessed over the internet on rental basis instead of using it by purchasing and installing it is called IAAS

EXAMPLE :

• Nirvanix-SDN(Storage Data Network)
• Amazon - S3(Simple Storage Service)
• EC2(Elastic Cloud Computing)
• Salesforce-Database.com

PAAS(PLATFORM AS A SERVICE) :

If a Platform that is used to develop a software applications can be accessed over the internet on rental basis instead of purchasing and installing it in our servers or Systems , it is called as a cloud Platform and this service is called PAAS.

EXAMPLE :

• Salesforce-Force.com (Uses Apex Language)
• Microsoft - Azure (.Net,C#,PHP)
• Google - App Engine (Java,Python)
• Amazon - Cloud Beans (Java)
• IBM - Work Load Developers (Java)

SAAS(SOFTWARE AS A SERVICE) :

If a software Application can be used over the internet on rental basis, instead of Purchasing and installing it in our systems, it is called a Cloud Applications and this service is called SAAS.

EXAMPLE :

• Salesforce - CRM
• Microsoft - Office 365
• Microsoft - Dynamix
• CA - Clarity
• Cisco - Webex

There are many cloud computing Service providers, but why people talk More about SalesForce

SalesForce is a CRM (SAAS(Software as a Service)and there are three roles namely Administrator, Developer and consultant. Many IT & Non-IT companies are using SalesForce CRM to expand their business by improving the efficiency of their manpower and also abbreviate infrastructure, software and hardware cost.

Some Best Sites to Refer :

1. How Cloud Computing Works.
2. How Cloud Storage Actually Works.
3. Core Cloud Storage.
4. Best Cloud Storage Examples.
5. Concerns about Cloud Storage.
6. Music Cloud Services

TYPES OF CLOUDS :

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 .

Though they are quite effective and eases an organization effort since everything is already there, it does face some criticism, esp on security related issue.

Private Clouds:

These are the types of clouds which exist 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:

They consist of external and internal providers, viz a mix of public and private clouds. Secure & critical apps are managed by an organization and the not-so-critical & 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.



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 for them, we all use public clouds services like Microsoft Office Web apps, Windows Live Mesh 2011, Google Docs, etc; whereas an enterprises will be having an interest in private & hybrid clouds.I will suggest them to check Microsoft Exchange online, Share Point online etc for this .