Cloud computing       

Clouds may be limited to a single organization (enterprise clouds), or be available to multiple organizations (public cloud).
Cloud computing relies on sharing of resources to achieve coherence and economies of scale.

What is cloud computing, in simple terms?

Cloud computing is the delivery of on-demand computing services -- from applications to storage and processing power -- typically over the internet and on a pay-as-you-go basis.

How does cloud computing work?

Cloud computing works by allowing client devices to access data over the internet, from remote servers, databases and computers.

An internet network connection links the front end (includes the accessing client device, browser, network and cloud software applications) with the back end, which consists of databases, servers and computers). The back end functions as a repository, storing data that is accessed by the front end.

Communications between the front and back ends are managed by a central server. The central server relies on protocols to facilitate the exchange of data. The central server uses both software and middleware to manage connectivity between different client devices and cloud servers. Typically, there will be a dedicated server for each individual application.

What are examples of cloud computing?

Cloud computing underpins a vast number of services. That includes consumer services like Gmail or the cloud back-up of the photos on your smartphone, though to the services which allow large enterprises to host all their data and run all of their applications in the cloud. Netflix relies on cloud computing services to run its its video streaming service and its other business systems too, and have a number of other organisations.

Cloud computing is becoming the default option for many apps: software vendors are increasingly offering their applications as services over the internet rather than standalone products as they try to switch to a subscription model. However, there is a potential downside to cloud computing, in that it can also introduce new costs and new risks for companies using it.

Cloud computing examples

Examples of cloudcomputing include:

Google Docs, Microsoft Office 365: Users can access Google Docs and Microsoft Office 365 through the internet. Users can be more productive because they can access work presentations and spreadsheets stored in the cloud at any time from anywhere on any device.

Email, Calendar, Skype, WhatsApp: Emails, calendars, Skype and WhatsApp take advantage of the cloud's ability to provide users with access to data remotely so they can access their personal data on any device, whenever and wherever they want.

Zoom: Zoom is a cloud-based software platform for video and audio conferencing that records meetings and saves them to the cloud, enabling users to access them anywhere and at any time.

AWS Lambda: Lambda allows developers to run code for applications or back-end services without having to provision or manage servers. The pay-as-you-go model constantly scales with an organization to accommodate real-time changes in data usage and data storage.

Cloud computing vs. traditional web hosting

A cloud service has three distinct characteristics that differentiate it from traditional web hosting:

• Users can access large amounts of computing power on demand. It is typically sold by the minute or the hour.
• It is elastic -- a user can have as much or as little of a service as they want at any given time.
• The service is fully managed by the provider (the consumer needs nothing but a personal computer and internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed internet, have accelerated interest in cloud computing.

History

     

Cloud computing was popularized with Amazon.com releasing its Elastic Compute Cloud product in 2006.

References to the phrase "cloud computing" appeared as early as 1996, with the first known mention in a Compaq internal document.

The cloud symbol was used to represent networks of computing equipment in the original ARPANET by as early as 1977, and the CSNET by 1981—both predecessors to the Internet itself. The word cloud was used as a metaphor for the Internet and a standardized cloud-like shape was used to denote a network on telephony schematics. With this simplification, the implication is that the specifics of how the endpoints of a network are connected are not relevant to understanding the diagram.

The term cloud was used to refer to platforms for distributed computing as early as 1993, when Apple spin-off General Magic and AT&T used it in describing their (paired) Telescript and PersonaLink technologies. In Wired's April 1994 feature "Bill and Andy's Excellent Adventure II", Andy Hertzfeld commented on Telescript, General Magic's distributed programming language: