Cloud Computing:The delivery of computing services—including servers, storage, databases, networking, software—over the internet ("the cloud") to offer faster innovation, flexible resources, and economies of scale.
Software as a Service (SaaS): A software distribution model in which applications are hosted by a third-party provider and made available to customers over the internet.
Data Center: A facility used to house computer systems and associated components, such as telecommunications and storage systems, which is where ASPs typically host their applications