Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network (typically the Internet). The name comes from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams. Cloud computing entrusts remote services with a user's data, software and computation.
There are many types of public cloud computing:
- Infrastructure as a service (IaaS)
- Platform as a service (PaaS)
- Software as a service (SaaS)
- Network as a service (NaaS)
- Storage as a service (STaaS)
- Security as a service (SECaaS)
- Data as a service (DaaS)
- Desktop as a service (DaaS - see above)
- Database as a service (DBaaS)
- Test environment as a service (TEaaS)
- API as a service (APIaaS)
- Backend as a service (BaaS)
- Integrated development environment as a service (IDEaaS)
- Integration platform as a service (IPaaS),
- see Cloud-based integration
In the business model using software as a service, users are provided access to application software and databases. The cloud providers manage the infrastructure and platforms on which the applications run. SaaS is sometimes referred to as “on-demand software” and is usually priced on a pay-per-use basis. SaaS providers generally price applications using a subscription fee.
Proponents claim that the SaaS allows a business the potential to reduce IT operational costs by outsourcing hardware and software maintenance and support to the cloud provider. This enables the business to reallocate IT operations costs away from hardware/software spending and personnel expenses, towards meeting other IT goals. In addition, with applications hosted centrally, updates can be released without the need for users to install new software. One drawback of SaaS is that the users' data are stored on the cloud provider’s server. As a result, there could be unauthorized access to the data.
End users access cloud-based applications through a web browser or a light-weight desktop or mobile app while the business software and user's data are stored on servers at a remote location. Proponents claim that cloud computing allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and enables IT to more rapidly adjust resources to meet fluctuating and unpredictable business demand.
Cloud computing relies on sharing of resources to achieve coherence and economies of scale similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services.
- ↑ Monaco, Ania (7 June 2012 [last update]). "A View Inside the Cloud". theinstitute.ieee.org (IEEE). Retrieved August 21, 2012.
- ↑ Oestreich, Ken, "Converged Infrastructure," CTO Forum, November 15, 2010". Thectoforum.com. 2010-11-15. Retrieved 2011-12-02.
- ↑ "The NIST Definition of Cloud Computing". National Institute of Standards and Technology. Retrieved 24 July 2011.
- ↑ "A network […] is shown schematically as a cloud", U.S. Patent 5,485,455, column 17, line 22, filed Jan 28, 1994
- The NIST Definition of Cloud Computing. Peter Mell and Timothy Grance, NIST Special Publication 800-145 (September 2011). National Institute of Standards and Technology, U.S. Department of Commerce.
- Guidelines on Security and Privacy in Public Cloud Computing. Wayne Jansen and Timothy Grance, NIST Special Publication 800-144 (December 2011). National Institute of Standards and Technology, U.S. Department of Commerce.
- Cloud Computing - Benefits, risks and recommendation for information security. Daniele Cattedu and Giles Hobben, European Network and Information Security Agency 2009.
- Fighting cyber crime and protecting privacy in the cloud. European Parliament - Directorate-General for Internal Policies. 2012
- Cloud Computing: What are the Security Implications?: Hearing before the Subcommittee on Cybersecurity, Infrastructure Protection, and Security Technologies of the Committee on Homeland Security, House of Representatives, One Hundred Twelfth Congress, First Session, October 6, 2011