NIST Cloud Computing Introduction and Definition
Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model is composed of five essential characteristics, three service models, and four deployment models.
According to the NIST, all true cloud environments have five key characteristics:
On-demand self-service: This means that cloud customers can sign up for, pay for and start using cloud resources very quickly on their own without help from a sales agent.
Broad network access: Customers access cloud services via the Internet.
Resource pooling: Many different customers (individuals, organizations or different departments within an organization) all use the same servers, storage or other computing resources.
Rapid elasticity or expansion: Cloud customers can easily scale their use of resources up or down as their needs change.
Measured service: Customers pay for the amount of resources they use in a given period of time rather than paying for hardware or software upfront. (Note that in a private cloud, this measured service usually involves some form of chargebacks where IT keeps track of how many resources different departments within an organization are using.)
Uses of cloud computing
You are probably using cloud computing right now, even if you don’t realise it. If you use an online service to send email, edit documents, watch movies or TV, listen to music, play games or store pictures and other files, it is likely that cloud computing is making it all possible behind the scenes. The first cloud computing services are barely a decade old, but already a variety of organisations—from tiny startups to global corporations, government agencies to non-profits—are embracing the technology for all sorts of reasons. Here are a few of the things you can do with the cloud:
- Create new apps and services
- Store, back up and recover data
- Host websites and blogs
- Stream audio and video
- Deliver software on demand
- Analyse data for patterns and make predictions
Top Benefits of Cloud Computing
Cloud computing is a big shift from the traditional way businesses think about IT resources. What is it about cloud computing? Why is cloud computing so popular? Here are 6 common reasons organisations are turning to cloud computing services:
Cloud computing eliminates the capital expense of buying hardware and software and setting up and running on-site datacenters—the racks of servers, the round-the-clock electricity for power and cooling, the IT experts for managing the infrastructure. It adds up fast.
Most cloud computing services are provided self service and on demand, so even vast amounts of computing resources can be provisioned in minutes, typically with just a few mouse clicks, giving businesses a lot of flexibility and taking the pressure off capacity planning.
- Global scale
The benefits of cloud computing services include the ability to scale elastically. In cloud speak, that means delivering the right amount of IT resources—for example, more or less computing power, storage, bandwidth—right when its needed and from the right geographic location.
On-site datacenters typically require a lot of “racking and stacking”—hardware set up, software patching and other time-consuming IT management chores. Cloud computing removes the need for many of these tasks, so IT teams can spend time on achieving more important business goals.
The biggest cloud computing services run on a worldwide network of secure datacenters, which are regularly upgraded to the latest generation of fast and efficient computing hardware. This offers several benefits over a single corporate datacenter, including reduced network latency for applications and greater economies of scale.
Cloud computing makes data backup, disaster recovery and business continuity easier and less expensive, because data can be mirrored at multiple redundant sites on the cloud provider’s network.
Types of cloud services: IaaS, PaaS, SaaS
Most cloud computing services fall into three broad categories: infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (Saas). These are sometimes called the cloud computing stack, because they build on top of one another. Knowing what they are and how they are different makes it easier to accomplish your business goals.
The most basic category of cloud computing services. With IaaS, you rent IT infrastructure—servers and virtual machines (VMs), storage, networks, operating systems—from a cloud provider on a pay-as-you-go basis. To learn more, see What is IaaS?
Platform as a service (PaaS)
Platform-as-a-service (PaaS) refers to cloud computing services that supply an on-demand environment for developing, testing, delivering and managing software applications. PaaS is designed to make it easier for developers to quickly create web or mobile apps, without worrying about setting up or managing the underlying infrastructure of servers, storage, network and databases needed for development. To learn more, see What is PaaS?
Software as a service (SaaS)
Software-as-a-service (SaaS) is a method for delivering software applications over the Internet, on demand and typically on a subscription basis. With SaaS, cloud providers host and manage the software application and underlying infrastructure and handle any maintenance, like software upgrades and security patching. Users connect to the application over the Internet, usually with a web browser on their phone, tablet or PC. To learn more, see What is SaaS?
Types of cloud deployments: public, private, hybrid
Not all clouds are the same. There are three different ways to deploy cloud computing resources: public cloud, private cloud and hybrid cloud.
Public clouds are owned and operated by a third-party cloud service provider, which deliver their computing resources like servers and storage over the Internet. Microsoft Azure is an example of a public cloud. With a public cloud, all hardware, software and other supporting infrastructure is owned and managed by the cloud provider. You access these services and manage your account using a web browser.
A private cloud refers to cloud computing resources used exclusively by a single business or organisation. A private cloud can be physically located on the company’s on-site datacenter. Some companies also pay third-party service providers to host their private cloud. A private cloud is one in which the services and infrastructure are maintained on a private network.
Hybrid clouds combine public and private clouds, bound together by technology that allows data and applications to be shared between them. By allowing data and applications to move between private and public clouds, hybrid cloud gives businesses greater flexibility and more deployment options.
How cloud computing works
Cloud computing services all work a little differently, depending on the provider. But many provide a friendly, browser-based dashboard that makes it easier for IT professionals and developers to order resources and manage their accounts. Some cloud computing services are also designed to work with REST APIs and a command-line interface (CLI), giving developers multiple options.
The World of Business Cloud Computing
Businesses can employ cloud computing in different ways. Some users maintain all apps and data on the cloud, while others use a hybrid model, keeping certain apps and data on private servers and others on the cloud.When it comes to providing services, the big players in the corporate computing sphere include:
- Google Cloud
- Amazon Web Services
- Microsoft Azure
- IBM Bluemix
Disadvantages of Cloud Computing
With all of the speed, efficiencies and innovations of cloud computing come risks.
Initially, security was seen as a detractor from using the cloud, especially when it came to sensitive medical records and financial information. While regulations are forcing cloud computing services to shore up their security and compliance measures, it remains an ongoing issue. Media headlines are constantly screaming about data breaches at this or that company, in which sensitive information has made its way into the hands of malicious hackers who may delete, manipulate or otherwise exploit the data (though, according to some reports, most of the data breeches have been with on-site systems, not those in the cloud). Encryption protects vital information, but if the encryption key is lost, the data disappears.
Servers maintained by cloud computing companies can fall victim to a natural disasters, internal bugs and power outages, too. And unfortunately, the geographical reach of cloud computing cuts both ways: A blackout in California could paralyze users In New York; a firm in Texas could lose its data if something causes its Maine-based provider to crash.
Ultimately, as with any new technology, there is a learning curve for employees and managers. But with many individuals accessing and manipulating information through a single portal, inadvertent mistakes can transfer across an entire system.
Source :https://azure.microsoft.com/en-in/overview/what-is-cloud-computing/https://www.investopedia.com/terms/c/cloud-computing.asphttps://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-145.pdf Wiki