Cloud computing is a computing model which enables businesses outsource to the management of data and applications to a service provider. The service provider hosts servers in a purpose built datacentre. The client can access computing resources as required, on demand, over a network connection. The result is an increase in scalability and a reduced upfront cost.
Cloud computing service providers deliver their services under three different models:
Infrastructure as a service (IaaS)
Infrastructure as a Service involves the hosting of physical or virtual machines in a data centre environment. Service providers supply resources on-demand as required by the client. This means that an organisation only pays for the resources that they utilise.
Platform as a service (PaaS)
Platform as a service is where a cloud providers deliver a computing platform. Generally this involves the hosting of an operating system or web server.
Software as a service (SaaS)
Software as a service is a model in which users are given access to application software and databases. The cloud provider manages the infrastructure and platforms that operate the applications. Software is installed and updated in the cloud and can be accessed at any time by users. This eliminates the need for businesses to install and manage software themselves.