Cloud - Platform of Services

Cloud favors organizations, stake holders, internet users and other resources a bunch of services on demand manner providing a metered service at multiple granularity for a specified level of quality (of service). Clouds can be classified into three types based on services delivered at different levels like software, hardware and firmware.

Types of Clouds

The following can be referred as main types of clouds which are currently in use and widely considered.

1. Infrastructure as a Service(IaaS)
2. Platform as a Service(PaaS)
3. Software as a Service(SaaS)

Infrastructure as a Service(IaaS)

Infrastructure as a Service or Hardware Cloud as the title implies cloud delivers infrastructure as its service. Instead of going for buy and deployment of computing resources in own data center, IaaS cloud provides grids or clusters or virtualized servers, networking technology, storage and data center space as a metered service on demand which are essential computing foundation resources. Example Amazon Web Services, EC2(Elastic Cloud Computing), Gogrid, Zimory, Elastichosts.

Platform as a Service(PaaS)

With Platform as a Service or Desktop cloud software developers can utilize the services to develop various applications without any need to install tools or frameworks on their actual desktops and even can easily host the developed applications with very minimal effort. PaaS typically makes use of dedicated APIs to control the behaviour of a server hosting engine which executes and replicates the execution according to user requests. One of the best examples is GoogleApps. It provides platform for software developers to build applications and also allows easily hosting the apps in no time. Other examples – Force.com, Google App Engine, Windows Azure (Platform) .

Software as a Service(SaaS)

 Software as a Service or Software cloud is a specialized software that runs on IaaS Cloud. Under this service, the service provider provides the software as a service. The customer can use the software as and when required and therefore eliminating the need of installing and running the software on the user’s desktop. The user can use the software service over the internet without dealing with efforts to install and manage the software resources. The user need to bother about access and upload of data and is free to access the data from anywhere in the world provided has access to internet. To quote there are many examples like DocStoc, Picasa, Flicker, Google Docs, Salesforce CRM, SAP Business by Design. etc.