We can presume cloud to be a very large server on which different services and data are stored and you can access all these for your work. The software and data that you access to your work doesn’t exist on your computer instead it’s on the server. This concept of using services not stored on your system in called Cloud Computing.
Cloud Computing is not an object in itself, rather it comprises services and databases that are accessed via web or any other private network. Examples of Cloud Computing Services includes Google Docs, Office 365, Dropbox, Skydrive, etc.
Type Of Cloud Computing:
Cloud Computing is composed of three service models and four development methods:
Lets first talk about Cloud Computing Service Models:
1. Infrastructure as a Service (IaaS).
2. Platform as a Service (PaaS).
3. Software as a Service (SaaS).
Infrastructure as a Service (IaaS):
The IaaS layer offers storage and Infrastructure resources that are needed to deliver the cloud services. It only comprises of the infrastructure or physical resources. Top IaaS Cloud Computing Companies are: Amazon, Rackspace, GoGrid, Microsoft, Terremark and Google.
Platform as a Service (PaaS):
PaaS provides the combination of both infrastructure and application. Hence, organizations using PaaS don’t have to worry, neither for infrastructure nor for service. Top PaaS Cloud Computing Companies are salesforce.com, Google, Concur Technologies, Arbia, Unisys, and Cisco.
Software as a Service (SaaS):
In the SaaS layer, Cloud service provider host the Software upon their server. It can be defined as a model in which applications and software are hosted upon the server and made available to customers over a network. Top SaaS Computing Companies are AWS, AppScale, CA Technologies, Engine Yard, SalesForce and Window Azure.
Cloud Computing Deployment Models:
1. Private Cloud
2. Public Cloud
3. Hybrid Cloud
4. Community Cloud
The Cloud infrastructure is operated solely for an organization. In simple words, we can say that such cloud models are dedicated to third party who wish to use it. It may be managed by the cloud computing provider or any other third party.
The Cloud Infrastructure is made available to the general pubic or a large industry group and owned by cloud provider.
It is a combination of two or more cloud infrastructure such as Private cloud, Community or public Cloud.
This Cloud Infrastructure is shared by several organizations from a specific community with common concerns (Security, jurisdiction, etc.)