How cloud computing works

Cloud computing provides a way of managing your IT resources online. Instead of buying IT resources from a hardware or a software shop, with cloud computing you are renting them from a cloud service provider, paying only for what you use.

Cloud computing is made up of four key elements:

• large-scale data centres hosted on remote servers
• services - eg software and hardware resources provided over the internet
• computers and other web-enabled devices, eg laptops, netbooks and smartphones
• broadband or 3G internet connection

Documents, emails, customer details and applications can all be stored remotely - ie 'in the cloud' - and accessed virtually and on-demand over the internet through a web browser.

Cloud deployment models

Cloud computing has four main models in terms of access and security options:

• public cloud - where services and infrastructure are available to the general public and provided off-site over the internet via a third-party provider
• private cloud - where services and infrastructure are available to a private customer and maintained on a private network either in-house or at the provider's data centre
• community cloud - where a group of customers access the resources of the same cloud service, usually sharing the same specific requirements that the service provides (eg high security or need for legal compliance)
• hybrid cloud - where you can mix and match public, community and private cloud resources based on your technical and business requirements

To work out which cloud model is best for your business, you should consider:

• how you currently use your IT systems and applications
• services which you would like to move to the cloud
• levels of service and support you will likely need
• your budget
• regulatory, governance or data protection issues related to those services

Read more about cloud service models.