You jargon-busting cloud terminology cheat-sheet
There aren't many other technological shifts that have generated quite as much jargon as cloud computing. Now that around 78% of organisations have formally adopted at least one cloud-based service, it's important to cut through the noise of cloud buzzwords and understand what cloud services can really do for us.
Virtualisation
Virtualisation is at the core of cloud computing. In its most basic form, virtualisation is about getting the most value out of your technology.
The capacity of physical severs is usually underused, so virtualisation creates a layer of abstraction between the underlying physical hardware and the operating systems they run. This enables several virtual machines to run on the same set of hardware and means that the physical components (the CPU, storage and memory) are used to their full capacity. "Virtualisation" is commonly used to describe server or "compute" virtualisation, but the principal has expanded to storage and networking and all aspects of the "software defined" data centre.
Public cloud
Public clouds are what most people imagine when they hear the term 'cloud computing'. They're shared pools of computing resources which exist on the premises of the cloud provider, delivering a range of free and paid-for services and infrastructure.
They are typically accessed on a self-service basis through a front-end portal, like a web-browser.
Private cloud
Conversely, private clouds contain dedicated resources only accessible by a single organisation. They're tightly controlled and highly customisable. Organisations can tailor the environment very closely to their needs, to save costs and provision resources exactly where they're needed.
Whilst they don't necessarily need to be on-premise (private clouds can exist off-site in 3rd party data centres and maintained through management portals), the organisation is still responsible for the configuration, maintenance and administration of their private environment.
Hybrid cloud
Hybrid cloud environments are a mix of public and private cloud services, distinct from one another and often procured from multiple sources.
Most organisations today possess very varied and complex needs from their cloud services, only some of which will demand the customisability and control of private clouds. As such, organisations may choose to separate the services they procure depending on their individual requirements and divide them between public and private environments accordingly.
Multi-tenancy
Multi-tenancy enables multiple organisations (or 'tenants') to make use of the same software instance or physical infrastructure simultaneously. This could be at the storage, OS or application level and it's one of the key reasons cloud computing can be so economical.
For more definitions and explanations, read the full Cloud Terminology Handbook here.