IN THIS CHAPTER
Defining cloud computing
Learning about cloud types
Understanding the paradigm shift that is cloud computing
Comparing the benefits and disadvantages of cloud systems
Cloud computing refers to applications and services that run on a distributed network using virtualized resources and accessed by common Internet protocols and networking standards. It is distinguished by the notion that resources are virtual and limitless and that details of the physical systems on which software runs are abstracted from the user.
In an effort to better describe cloud computing, a number of cloud types have been defined. In this chapter, you learn about two different classes of clouds: those based on the deployment model and those based on the service model. The deployment model tells you where the cloud is located and for what purpose. Public, private, community, and hybrid clouds are deployment models.
Service models describe the type of service that the service provider is offering. The best-known service models are Software as a Service, Platform as a Service, and Infrastructure as a Service—the SPI model. The service models build on one another and define what a vendor must manage and what the client's responsibility is.
Cloud computing represents a real paradigm shift in the way in which systems are deployed. The massive scale of cloud computing systems was enabled by the popularization of the Internet and the growth of some large service companies. ...