Cloud computing is a potentially cost-efficient model for provisioning processes, applications and services while making IT management easier and more responsive to the needs of the business. These services - computation services, storage services, networking services, whatever is needed - are delivered and made available in a simplified way - "on demand" regardless of where the user is or the type of device they're using.
Cloud computing describes both a platform and a type of application. A cloud computing platform dynamically provisions, configures, reconfigures, and deprovisions servers as needed. Cloud applications are those that are extended to be accessible through the Internet. These cloud applications use large data centers and powerful servers that host Web applications and Web services.
What are the benefits of Cloud Computing ?
. Cost is greatly reduced and capital expenditure is converted to operational expenditure. This lowers barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and minimal or no IT skills are required for implementation
. Device and location independence enable users to access systems using a web browser regardless of their location or what device they are using, e.g., PC, mobile. As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet the users can connect from anywhere.
. Multi-tenancy enables sharing of resources and costs among a large pool of users, allowing for:
° Centralization of infrastructure in areas with lower costs.
° Peak-load capacity increases (users need not engineer for highest possible load-levels)
° Utilisation and efficiency improvements for systems that are often only 10-20% utilised.
. Reliability improves through the use of multiple redundant sites, which makes it suitable for business continuity and disaster recovery. Nonetheless, most major cloud computing services have suffered outages and IT and business managers are able to do little when they are affected.