Authors: Peter Mell and Tim Grance
Version 15, 10-7-09
National Institute of Standards and Technology, Information Technology Laboratory
Note 1: Cloudcomputing is still an evolving paradigm. Its definitions, use cases, underlying
technologies, issues, risks, and benefits will be refined in a spirited debate by the public and
private sectors. Thesedefinitions, attributes, and characteristics will evolve and change over time.
Note 2: The cloud computing industry represents a large ecosystem of many models, vendors,
and market niches. Thisdefinition attempts to encompass all of the various cloud approaches.
Definition of Cloud Computing:
Cloud computing is a model for enabling convenient, on-demand network access to a shared
pool ofconfigurable computing resources (e.g., networks, servers, storage, applications, and
services) that can be rapidly provisioned and released with minimal management effort or
service provider interaction.This cloud model promotes availability and is composed of five
essential characteristics, three service models, and four deployment models.
On-demand self-service. Aconsumer can unilaterally provision computing capabilities,
such as server time and network storage, as needed automatically without
requiring human interaction with each service’s provider.
Broadnetwork access. Capabilities are available over the network and accessed through
standard mechanisms that promote use by heterogeneous thin or thick client
platforms (e.g., mobile phones, laptops,and PDAs).
Resource pooling. The provider’s computing resources are pooled to serve multiple
consumers using a multi-tenant model, with different physical and virtual
resources dynamically assignedand reassigned according to consumer demand.
There is a sense of location independence in that the customer generally has no
control or knowledge over the exact location of the provided resources...