The term is widely used metaphor to describe the Internet. There are many definitions of the 'Cloud', but in simple terms what does it mean?
The concept of the ‘Cloud’ is often compared by analogy to an electricity grid where in the latter consumers will run a whole variety of electrical devices using the mains power without necessarily knowing or needing to know where the power was generated or how it was provided. In the same way, the cloud provides a whole range of computing services, such as data access and storage and software, that don’t need the user to know the location or the configuration of the systems that are delivering the services.
Cloud computing is a distributed computing paradigm which allows a third party to provide managed computer resources in an on-demand fashion for people to run their own services. The provider manages this by running large data centres of commodity computers, harnessing the economies of scale to charge its users per unit usage time. So, in a way, it is computer wholesaling.
Additional information about the cloud can be found in Project Resources, including useful definitions in the Glossary and links to websites to visit.