Cloud computing describes concepts that involve a large number of computers connected through a communication network such as the Internet.Cloud computing is a synonym for distributed computing over a network, and means the ability to run a program or application on many connected computers at the same time.
Cloud is abstraction for set of servers which host products and services from a remote location.Buyer need not to worry about the maintenance or purchase of this infrastructure/services.Buyer just need to pay on demand basis (Pay per user/Utility computing).
An executive at a large corporation who is making sure that all of employees have right infrastructure and software they need to complete their job. Purchasing computers and software for everyone and managing it can be big investment for organization.As well as, it is hassle to maintain information about infrastructure and license information.Cloud could be a best solution for this executive. Cloud solutions are pay per basis. Cloud solutions removes worry and extra work related to maintenance of infrastructure and software licenses.
Cloud Computing has 3 fundamental models of Service:
Controlled cloud: Controlled cloud services are not publicly available; users are specifically authorized by services vendors.
Private cloud: Private cloud is cloud infrastructure operated solely for a single organization.
Public cloud: A cloud is called a “public cloud” when the services are rendered over a network that is open for public use.
Community cloud: Community cloud shares infrastructure between several organizations from a specific community with common concerns.
Hybrid cloud: Hybrid cloud is a composition of two or more clouds (private, community or public) that remain unique entities but are bound together, offering the benefits of multiple deployment models. Hybrid cloud can also mean the ability to connect collocation, managed and/or dedicated services with cloud resources.
Distributed cloud: Cloud computing can also be provided by a distributed set of machines that are running at different locations, while still connected to a single network or hub service.