cloud computing

a type of computing in which computing resources are shared via the Internet, rather than the use of local servers or personal computing devices

Flick a switch and you've got access to electricity, turn on a tap and you've got water, and now … connect to the Internet, and you can hook up to all the computing power you might ever need – therein lies the philosophy behind cloud computing.

Deemed by some to be the next big thing in computer innovation, cloud computing is based on the idea that, rather than each company or individual being set up with their own computing devices for data storage and manipulation, computing resources can be pooled and shared via the Internet. The goal of cloud computing is therefore a shared IT infrastructure providing easy access to (powerful) computer resources which are geared towards users' needs – they can be expanded or scaled down as the user requires.

Cloud computing has two main subtypes: a public cloud, in which a service provider makes computing resources available to the general public over the Internet, and a private cloud, also sometimes referred to as a corporate or internal cloud, in which a network of computing resources serves a particular group of users and is maintained by the organisation that it serves.

although the flexibility of cloud computing offers many benefits to users, the concept has also sparked controversy in relation to concerns about data privacy and security

In the current economic climate, there is a growing interest in cloud computing as a financially advantageous approach to IT. Users of cloud computing can avoid expenditure on hardware, software and services, only paying the provider for what they actually use in much the same way as you would pay an electricity bill. In this sense there are parallels between cloud computing and what is sometimes referred to as utility computing, the marketing of computing resources as a metered service like a public utility.

Although the flexibility of cloud computing offers many benefits to users, the concept has also sparked controversy in relation to concerns about data privacy and security. A high-profile example of the 'dangers' of cloud computing occurred in October 2009, when T-Mobile announced that user data for its Sidekick messaging device had been lost after a failed system upgrade. With the Sidekick smartphone, a user's data (contacts, calendar entries, to-do lists, etc.) is stored in a 'cloud' to which there is a temporary connection when it is turned on, rather than kept on the device itself.

Background – cloud computing

The term cloud computing first appeared in 2007, though the underlying concept dates as far back as the early 1960s, when American computer scientist John McCarthy was the first to suggest that computing resources might one day be sold as a utility like water or electricity.

The word cloud is used as a metaphor for the Internet, based on how the Internet is often depicted in computer network diagrams.