Why Cloud Computing?
Agility is improved with users’ ability to rapidly and inexpensively re-provision technological infrastructure resources.
Cost is greatly reduced and capital expenditure is converted to operational expenditure. This ostensibly 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.
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, users can connect from anywhere.
Multi-tenancy enables sharing of resources across a large pool of users thus allowing for:
1) Centralization of infrastructure in locations with lower costs (such as space, electricity, etc.)
2) Peak-load capacity increases (users need no engineer for highest possible load-levels)
3) Utilization and efficiency improvements
Reliability improves through the use of multiple redundant sites, which makes cloud computing suitable for business continuity and disaster recovery.
Scalability via dynamic (“on-demand”) provisioning of resources on a fine-grained, self-service basis near real-time. Performance is monitored, and consistent.
Security could improve due to centralization of data, increased security-focused resources. Security is often as good as or better than under traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford.Providers typically log accesses, but accessing the audit logs themselves can be difficult or impossible. Furthermore, the complexity of security is greatly increased when data is distributed over a wider area and / or number of devices.
Maintenance cloud computing applications are easier to maintain, since they don’t have to be installed on each user’s computer. They are easier to support and to improve since the changes reach the clients instantly.
Example: Google Apps
