CDN (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.

Cloud Application
The top layer of the Cloud Computing Stack where applications interact with client web browsers. Examples: Gmail and Salesforce.com.

Cloud Broker
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.

Force.com
Force.com is the Platform as a Service (PaaS) offering from Salesforce.com. See also: PaaS

Hybrid Cloud
A combination of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability.

IaaS (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.

Multi tenancy
Multi tenancy is the property of multiple systems, applications or data from different enterprises hosted on the same physical hardware. Multitenancy is common to most cloud-based system.

PaaS (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.

Private Cloud
Services offered over the Internet or over a private internal network to only select users, not available to the general public.

Public Cloud
Services offered over the public Internet and available to anyone who wants to purchase the service.

SaaS (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).

SLA (Service Level Agreement)
An SLA is contract between a provider and a consumer that specifies consumer requirements and the provider’s commitment to them. Typically an SLA includes items such as uptime, privacy, security and backup procedures.

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.