A subscription-based pricing model is a payment structure that allows a customer or organization to purchase or subscribe to a vendor's IT services for a specific period of time for a set price.
The Topology and Orchestration Specification for Cloud Applications (TOSCA) is an open-source language used to describe the relationships and dependencies between services and applications that reside on a cloud computing platform.
A vertical cloud is a set of cloud computing services optimized for use in a particular industry, or for a specific business model.
The Azure Fabric Controller (FC) is the part of the Windows Azure platform that monitors and manages virtual and physical servers and coordinates resources for software applications.
XaaS is a general, collective term that refers to the delivery of anything as a service.