What is Cloud Computing?

Ramnath K. Chellappa is credited with associating the term ‘cloud computing’ with the provision of software as a service over the internet (Giordanelli and Mastroianni, 2010), specifically in the context of small-to-medium enterprises (SMEs), where he suggested that the scope of such a service would be limited by cost of access rather than technology (Ray, 2018). This showed great foresight in 1997, a time when local area networks were the norm.

A little over a decade later, it became a buzzword used by providers including Oracle, Microsoft, Yahoo!, Google, Amazon Web Services, and IBM (ibid).

The National Institute of Standards and Technology has the most cited definition of cloud computing as a “model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources” (Mell and Grance, 2011).

Their definition is then broadened to factor in the following essential elements of service:

• On demand with elastic capability subject only to pre-set limitations metered by the provider and agreed to by the user (including, for example, number of accounts, amount of data, processing power, etc.)
• Self-service by the end user without the need to engage with human help by the service provider across multiple tools such as mobile phones or laptops.
• Provided by a range of resources from processors to storage “that the customer generally has no control or knowledge over the exact location of the provided resources” (ibid; my emphasis).

Service is no longer limited to software provision and is now more often expressed in terms of “computing resources” or “IT services” as demonstrated in the table below. Within this list, only Amazon Web Services draws the direct connection between cloud computing and data centres.