Cloud computing is a computing paradigm, where a large pool of systems are connected in private or public networks, to provide dynamically scalable infrastructure for application, data and file storage. So, the cost of computation, application hosting, content storage and delivery is reduced significantly.
Cloud Computing Models:Cloud Providers offer services that can be grouped into three categories.
- Infrastructure as a Service (Iaas): IaaS provides basic storage and computing capabilities as standardized services over the network. Servers, storage systems, networking equipment, data center space etc. are pooled and made available to handle workloads.
- Platform as a Service (Paas): A layer of software, or development environment is encapsulated & offered as a service, upon which other higher levels of service can be built. PaaS providers offer a predefined combination of OS and application servers.
- Software as a Service (SaaS): In this model, a complete application is offered to the customer, as a service on demand.
Public and Private Clouds:
Once you understand the basic premise of cloud computing, Enterprises can choose to deploy applications on Public, Private or Hybrid clouds.
Public Cloud:Public clouds are the most common way of deploying cloud computing. The cloud resources (like servers and storage) are owned and operated by a third-party cloud service provider and delivered over the Internet. With a public cloud, all hardware, software and other supporting infrastructure is owned and managed by the cloud provider. In a public cloud, you share the same hardware, storage and network devices with other organisations or cloud “tenants.” You access services and manage your account using a web browser. Public cloud deployments are frequently used to provide web-based email, online office applications, storage and testing and development environments.
Private Cloud:A private cloud consists of computing resources used exclusively by one business or organisation. The private cloud can be physically located at your organisation’s on-site datacenter or it can be hosted by a third-party service provider. The services and infrastructure are always maintained on a private network and the hardware and software are dedicated solely to your organisation. Private clouds are often used by government agencies, financial institutions, any other mid- to large-size organisations with business-critical operations seeking enhanced control over their environment.
Hybrid Cloud:Often called “the best of both worlds,” hybrid clouds combine on-premises infrastructure, or private clouds, with public clouds so organisations can reap the advantages of both. In a hybrid cloud, data and applications can move between private and public clouds for greater flexibility and more deployment options.