Development models of Cloud Computing

            There are three types of development models of cloud computing, which are a private cloud, public cloud & hybrid cloud. Private cloud computing services are only for one organization. The private cloud may be managed by the organization itself, or a third party might be providing the cloud services to the organization. Another type of cloud service is the public cloud, which is available to many organizations who are working in a specific region. The public cloud services might be available free of cost to the organizations. Public cloud provide services to the general public but with some limitation. For instance, public cloud access to only publically available information it does not support to access private and restricted information. Another type is known as a hybrid cloud which the combination of both public & private cloud. Hybrid cloud provide access to both internal and external resources. In hybrid cloud some resources could be offered to the internal users only while other public resources can be made available for the general public without any restrictions and security limits. Other than these three major types some other models based on the infrastructure types are related to the VPN connection and specific communities.

Services models of cloud computing

         Service models of cloud computing has three main types known as IaaS, PaaS, and SaaS models. Cloud computing on the basis of infrastructure ownership are as public cloud, hybrid cloud, private cloud, virtual private cloud, and community cloud. Somehow in this section main focus is on the service based models of cloud computing. Infrastructure-as-a-service is abbreviated to IaaS. While PaaS and SaaS are the abbreviations of Platform as a service and Software as a service.  Each service model of cloud computing has its own functions, features and limitations.

Infrastructure-as-a-service (IaaS) of Cloud Computing

            The most important cloud computing model is Infrastructure-as-a-service (IaaS) model. It provide access to the workplaces and organizations to computing storage capacities and power through the use of cloud provider’s hardware. As a result of this they get control over the infrastructure to ensure application running in the cost-effective way. Somehow, it remains under the responsibility of the organization to manage and update operating system used to run applications. While on the other hand, IaaS provider takes the responsibility to manage hardware and plan for capacity and security management.       

         Organizations using this model monitor resources and apps to meet with the demand and requirements. Amazon web services provide various products related to IaaS cloud hosting that are really easy to be purchased by the organizations for a better cloud computing model and effective infrastructure. Microsoft Azure is a key product that is fully functional and supportive for IaaS and PaaS service models of cloud computing in the organizations.       

Platform-as-a-service (PaaS)

         Platform as a service (PaaS) is another service type model in which PaaS providers provide access to the developers to build new online applications in the given platforms. In these platforms, developers can store several kinds of apps to publish later. Developer use code for apps. In Platform as a service (PaaS) model, developers are not required to manage and plan hardware, security, and apps capacity like IaaS service model. Platform as a service (PaaS) provider deal with all these managerial tasks by themselves and provide a ready to use platform to the developers to create and publish their own apps. A fine example is the game angry bird published by the developers at Google Apps Engine.