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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 common 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.
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 companies to avoid
upfront infrastructure costs, and focus on projects that
differentiate their businesses instead of infrastructure.[1]
Proponents also 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.[1][2][3]
In the business model using software as a service, users are
provided access to application software and databases. Cloud
providers manage the infrastructure and platforms that run the
applications. 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.
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.[4] At the foundation of cloud
computing is the broader concept of converged infrastructure and
shared services.