You don't have to know everything about cloud computing, but a familiarity with the terminology will help you follow the trends and industry developments. This glossary offers a rundown of the terms you're likely to come across.
Cloud computing is one of the hottest topics in IT these days, with Microsoft, Google, Amazon, and other big players joining in the fray. However, the technology brings with it new terminology that can be confusing. Here are some common cloud-related terms and their meanings.
Note: This glossary is also available as a PDF download.
Advertising-based pricing model
A pricing model whereby services are offered to customers at low or no cost, with the service provider being compensated by advertisers whose ads are delivered to the consumer along with the service.
Amazon's Elastic Compute Cloud Web service, which provides resizable computing capacity in the cloud so developers can enjoy great scalability for building applications.
Amazon Simple Storage Services -- Amazon's cloud storage service.
Content delivery network -- A system consisting of multiple computers that contain copies of data, which are located in different places on the network so clients can access the copy closest to them.
A metaphor for a global network, first used in reference to the telephone network and now commonly used to represent the Internet.
An entity that creates and maintains relationships with multiple cloud service providers. It acts as a liaison between cloud services customers and cloud service providers, selecting the best provider for each customer and monitoring the services.
Cloud operating system
A computer operating system that is specially designed to run in a provider's datacenter and be delivered to the user over the Internet or another network. Windows Azure is an example of a cloud operating system or "cloud layer" that runs on Windows Server 2008. The term is also sometimes used to refer to cloud-based client operating systems such as Google's Chrome OS.
Cloud Oriented Architecture
A term coined by Jeff Barr at Amazon Web Services to describe an architecture where applications act as services in the cloud and serve other applications in the cloud environment.
The ability to move applications and data from one cloud provider to another. See also Vendor lock-in.
A company that provides cloud-based platform, infrastructure, application, or storage services to other organizations and/or individuals, usually for a fee.
A service that allows customers to save data by transferring it over the Internet or another network to an offsite storage system maintained by a third party.
Replacing traditional IT services with cloud services.
Connecting multiple cloud computing environments.
Software that enables creating, deploying, running, or managing applications in the cloud.
A group of linked computers that work together as if they were a single computer, for high availability and/or load balancing.
Consumption-based pricing model
A pricing model whereby the service provider charges its customers based on the amount of the service the customer consumes, rather than a time-based fee. For example, a cloud storage provider might charge per gigabyte of information stored. See also Subscription-based pricing model.
A feature that allows customers to provision, manage, and terminate services themselves, without involving the service provider, via a Web interface or programmatic calls to service APIs.
A term used in the business world to describe innovations that improve products or services in unexpected ways and change both the way things are done and the market. Cloud computing is often referred to as a disruptive technology because it has the potential to completely change the way IT services are procured, deployed, and maintained.
The ability to dynamically provision and de-provision processing, memory, and storage resources to meet demands of peak usage without worrying about capacity planning and engineering for peak usage.
Public or private cloud services that are provided by a third party outside the organization.
Google App Engine
A service that enables developers to create and run Web applications on Google's infrastructure and share their applications via a pay-as-you-go, consumption-based plan with no setup costs or recurring fees.
Google's SaaS offering that includes an office productivity suite, email, and document sharing, as well as Gmail, Google Talk for instant messaging, Google Calendar and Google Docs, spreadsheets, and presentations.
Hardware as a service; see IaaS.
An Internet-based or Web-based application software program that runs on a remote server and can be accessed via an Internet-connected PC or thin client. See also SaaS.
A networking environment that includes multiple integrated internal and/or external providers.
Infrastructure as a service -- Cloud infrastructure services, whereby a virtualized environment is delivered as a service over the Internet by the provider. The infrastructure can include servers, network equipment, and software.
IBM Smart Business
IBM's cloud solutions, which include IBM Smart Business Test Cloud, IBM Smart Analytics Cloud, IBM Smart Business Storage Cloud, IBM Information Archive, IBM Lotus Live, and IBM LotusLive iNotes.
A type of private cloud whose services are provided by an IT department to those in its own organization.
A Web-based application that combines data and/or functionality from multiple sources.
Microsoft cloud services that provide the platform as a service (see PaaS), allowing developers to create cloud applications and services.
Software that sits between applications and operating systems, consisting of a set of services that enable interoperability in support of distributed architectures by passing data between applications. So, for example, the data in one database can be accessed through another database.
A model by which a customer can purchase cloud services as needed; for instance, if customers need to utilize additional servers for the duration of a project, they can do so and then drop back to the previous level after the project is completed.
Platform as a service -- Cloud platform services, whereby the computing platform (operating system and associated services) is delivered as a service over the Internet by the provider.
Pay as you go
A cost model for cloud services that encompasses both subscription-based and consumption-based models, in contrast to traditional IT cost model that requires up-front capital expenditures for hardware and software.
Services offered over the Internet or over a private internal network to only select users, not available to the general public.
Services offered over the public Internet and available to anyone who wants to purchase the service.
Software as a service -- Cloud application services, whereby applications are delivered over the Internet by the provider, so that the applications don't have to be purchased, installed, and run on the customer's computers. SaaS providers were previously referred to as ASP (application service providers).
An online SaaS company that is best known for delivering customer relationship management (CRM) software to companies over the Internet.
The act of moving from one cloud service or vendor to another.
The company or organization that provides a public or private cloud service.
Service level agreement -- A contractual agreement by which a service provider defines the level of service, responsibilities, priorities, and guarantees regarding availability, performance, and other aspects of the service.
Subscription-based pricing model
A pricing model that lets customers pay a fee to use the service for a particular time period, often used for SaaS services. See also Consumption-based pricing model.
Online computing or storage sold as a metered commercial service in a way similar to a public utility
Dependency on the particular cloud vendor and difficulty moving from one cloud vendor to another due to lack of standardized protocols, APIs, data structures (schema), and service models.
A cloud computing environment that is optimized for use in a particular industry, such as health care or financial services.
Virtual private data center
Resources grouped according to specific business objectives.
Virtual private cloud -- A private cloud that exists within a shared or public cloud, e.g., the Amazon VPC that allows Amazon EC2 to connect to legacy infrastructure on an IPsec VPN.
Windows Live Services
Microsoft's cloud-based consumer applications, which include Windows Live Mail, Windows Live Photo Gallery, Windows Live Calendar, Windows Live Events, Windows Live Skydrive, Windows Live Spaces, Windows Live Messenger, Windows Live Writer, and Windows Live for Mobile.
Debra Littlejohn Shinder, MCSE, MVP is a technology consultant, trainer, and writer who has authored a number of books on computer operating systems, networking, and security. Deb is a tech editor, developmental editor, and contributor to over 20 additional books on subjects such as the Windows 2000 and Windows 2003 MCSE exams, CompTIA Security+ exam, and TruSecure's ICSA certification.