Gabriella Griffith puts the cloud into plain English
Cloud bursting is the practice by businesses of only using cloud services when its local IT infrastructure is near maximum capacity and avoids the need to have unused capacity to deal with usage spikes.
Cloud computing is the process of sharing computing resources rather than using local servers to handle applications. Your computing is delivered over the internet rather than your own machine or server.
Cloud washing is an attempt by a vendor to rebrand an old product or service by associating it with the trendy term “cloud”. These old products re-emerge, tweaked a little, riding on the coat-tails of the cloud buzzword.
Community cloud is a service for use by a group of companies or public sector organisations. This kind of cloud helps separate organisations that might need to co-ordinate with each other without opening the service up to the public.
Elastic computing is the dynamic allocation of IT resources. If an organisation only requires cloud service for a few hours of the day, the cloud provider can give that service to another user for the rest of the time.
Hosting stack refers to the hierarchy of services offered in the sphere of cloud computing, also described as a value chain. The further into the stack you go, the more the cloud is doing for you. IaaS, PaaS and SaaS are the stack’s layers.
Hybrid cloud is an amalgamation of public and private clouds. It allows companies to use both in parallel as part of their IT strategy and is a useful migration tool.
Infrastructure as a service (IaaS) is the first rung on the stack and means using the cloud for things such as processing, storage, memory and networking. It saves businesses having to buy and look after expensive infrastructure.
Multi-tenancy refers to the sharing of servers which run the same operating system but with metadata and data broken down into many distinct parts that each belong to a company. The companies cannot access others’ parts, but they are all run on the same technology stack.
Platform as a service (PaaS) is the next step up and gives a platform and tools for developers of software to create and launch their own applications. Examples are Microsoft Azure and Force.com.
Private cloud is a service built to serve one company or group only. This offers the flexibility which cloud computing is loved for, but with the security of a dedicated IT system.
Public cloud is a network of computing which offers applications and storage to the general public over the internet. This means they span multiple locations and countries with many users having discrete access at any one time.
Software as a service (SaaS) refers to software and applications that are accessed over the internet. The use of these doesn’t require installation, unlike desktop applications. Examples include Google Docs and Facebook.
Utility computing refers to the act of paying for the use of applications and software on a pay-as-you-go basis rather than installing and maintaining them yourself. Just in the way we pay for utilities like gas and electricity.