Cloud Computing, a paradigm of computing is one of the easiest means of access and data storage over the Internet, rather than storing data on the hard disk. It is also recognized as a large number of systems that helps us stay connected with private or public networks and to ensure dynamically scalable infrastructure for data storage and application files.With the launch of this technology it is significantly shortened content storage, delivery, the cost of computing, and application hosting. It has a potential transformation of a data center of a capital-intensive set to a variable average price.
According to a research industries - Forrester defines cloud computing as a pool of computing infrastructure abstract, highly scalable and managed capable of hosting end-customers applications and billed by consumption. Whereas, the National Institute of Standards and Technology (NIST) has developed the definition of cloud computing as a model that allows convenient access to the card network to a shared pool of configurable computing resources (eg, whole networks , servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction quickly.
The feature of cloud computing consists of self-service, where a customer can request and manage their own computing resources. Access to extensive service network allows is available for private networks or the Internet. This technology provides a set of shared resources, where the customer is based on a set of computing resources, usually in a remote data center.
service models Cloud Computing
Cloud computing services are grouped into three categories - Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) and Infrastructure-as-a-Service (IaaS).
Software-as-a-Service (SaaS)
In this service model, applications cloud-based customer offered as a service on demand. It is a unique instance of the service running on remote computers "in the cloud", which are owned and operated by others and connected to users' computers via the Internet and, usually, a web browser. social networking sites like Facebook, Twitter, Flickr and Google are examples of SaaS, although users can access the services through any device with Internet access.
Platform-as-a-Service (PaaS)
The model platform as a service (PaaS) is a level above configuration software-as-a-Service and provides hardware, network and operating system, so that a customer can design their own application and software. In order to meet the application requirements such as scalability and manageability, a predefined combination of the operating system OS and application servers it is offered by PaaS providers such as J2EE restricted platform LAMP (Linux , Apache, MySQL and PHP), etc., for example, at all stages of the process to develop, test and finally host their websites, web developers can use individual PaaS environments.