What are the characteristics of Cloud Computing?

Service Oriented: The defining characteristics of cloud computing is the service oriented feature. All the IT related services are hosted in cloud infrastructure. Companies should not have to buy expensive servers, network equipment’s and invest on expensive manpower. All they need is to subscribe to any cloud service provider and get what they want. In this way, we can decrease our capital expenditure and move to operate via Operating expenditure. 

Broad Network Access: Cloud Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms such as mobile phones, laptops and PDAs. 

On Demand: A consumer can provision computing capabilities, such as server processing and network storage, as needed automatically without requiring human interaction with each service’s provider. computer services such as email, applications, network or server service can be provided without requiring human interaction with each service provider. Cloud service providers providing on demand self-services include Amazon Web Services (AWS), Microsoft, Google, IBM and Salesforce.com. 

Reliability, Elasticity and scalability: The cloud is reliable in the sense that the infrastructure setup for cloud is robust and backed up for high availability. It is some resilient replication and backup strategy that is targeted for huge customer base. The cloud is elastic, meaning that resource allocation can get bigger or smaller depending on demand. Elasticity enables scalability, which means that the cloud can scale upward for peak demand and downward for lighter demand. Scalability also means that an application can scale when adding users and when application requirements change.  

Resource Pooling (Processor, Memory, and Storage): Cloud infrastructure should have features of resource pooling i.e. resources (CPU, Memory, Disk) should be categorized in a hierarchy as per the need of computing. Resource pooling is mainly used for utilizing servers up to its potential. Since most of the times server  resources are unused, we can use the concept of virtualization to pool its resources. 

Measured Service (Pay per Use): Cloud computing resource usage can be measured, controlled, and reported providing transparency for both the provider and consumer of the utilized service. Cloud computing services use a metering capability which enables to control and optimize resource use. This implies that just like air time, electricity or municipality water IT services are charged per usage metrics – pay per use. The more you utilize the higher the bill. Just as utility companies sell power to subscribers, and telephone companies sell voice and data services, IT services such as network security management, data center hosting or even departmental billing can now be easily delivered as a contractual service. 

Multi Tenancy: Multi tenancy refers to a principle in IT infrastructure where a single instance of the software runs on a server, serving multiple client organizations (tenants). With a multi-tenant architecture, a designed to virtually partition its data and configuration, and each client organization works with a customized virtual application instance. Each customer does its own work without interfering other customer even though they are hosted at the same platform.