In computer science, the term cloud refers to a network or Internet. Cloud Computing is the on-demand availability of computer system resources, that are located at remote locations.
The NIST’s (National Institute of Standards and Technology) definition of cloud computing includes the following “five essential characteristics”:
- On-Demand Self Service: Cloud Computing lets users use web services and resources on demand.
- Broad Network Access: Cloud Computing services can be accessed from anywhere and at any time.
- Resource Pooling: Cloud Computing resources are pooled to serve multiple users using a multi-tenant model.
- Rapid Elasticity: Automatic scaling (outward and inward) of resources as per demand.
- Measured Service: Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.
A2Z of Cloud Computing – Service Models
Cloud computing services based on three service models. They are:
- Infrastructure-as-a-Service (IaaS): In IaaS, the user can deploy and run any software, which can include operating systems and applications. The user does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications.
- Platform-as-a-Service (PaaS): In PaaS, the user can deploy any application created using programming languages, libraries, services, and tools supported by the provider. The user doesn’t manage any infrastructure.
- Software-as-a-Service (SaaS): In SaaS, the user can the software(s) provided by the service provider. The user doesn’t manage any infrastructure.
A2Z of Cloud Computing – Deployment Models
There are four major deployment models. They are:
- Private Cloud: In Private Cloud, the cloud infrastructure is accessible within an organisation.
- Public Cloud: In Public Cloud, the cloud infrastructure is open for public use.
- Community Cloud: In the Community Cloud, the cloud infrastructure is shared between several organizations.
- Hybrid Cloud: Hybrid Cloud is a combination of two or more clouds. In this system, an organization may store sensitive data on a private cloud application, but interconnect that application to a business intelligence application provided on a public cloud as a software service.
The biggest advantage of cloud computing – it lowers expenditure on IT and infrastructure. But, experts have raised security-related concerns. Cloud computing services are provided by third parties and this poses privacy concerns. They can access the data which is present in the cloud. They might even alter it (accidentally).