Cloud computing is a model for on-demand access to a shared pool of computing resources. The computing can be delivered over the Internet (public cloud computing) or within an organization (private cloud computing). The use of the cloud provides a number of opportunities: It enables services to be used without an understanding of their infrastructure.Cloud computing works using economies of scale. It lowers the outlay expense for start up companies as they would no longer need to buy their own software or servers. Cost would be by on-demand pricing.Data and services are stored remotely but are accessible from anywhere.Maintenance and change management 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.Agility improves with users' ability to rapidly and inexpensively reprovision technological infrastructure resources.Cost is reported to be 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.Scalability via dynamic provisioning of resources on a fine-grained, self-service basis near real-time is provided, without users having to engineer for peak loads. As with any other technology, companies\/organizations must address a wide range of cloud computing risks: The use of cloud computung creates dependence on third party companies and that could possibly limit flexibility, control, and innovation. The biggest players could monopolise the market. Some argue that the use of supercomputers is a return to the time of mainframe computing that the personal computer (PC) was a reaction against.Security could be a big issue. Software-as-a-service (SAAS) vendors may store data in data-centers all over the world. Those data-centers may hold information from many different businesses, even competitors. The organization should determine if it is appropriate to store such types of information as client lists, pricing, intellectual property, etc. on external servers.There are risks related to having a critical software application developed and managed by an outside entity. If a vendor\u2019s software application ceases to function, the organization may experience financial losses as well as damage to its image and reputation.There are also issues relating to policy and access. If data are stored abroad, whose Freedom of Information Policy ( FOI) should be adhered to? What happens if the remote server goes down? How will files and data then be accessed?Employee productivity will drop if internet connectivity is down for an extended period of time. Redundant high speed Internet lines may be needed to help counteract this possibility. At Tridens we prefer using private cloud, which is used exclusively by your company\/organization. With private cloud, your company\/organization takes control of security, lock-in, and reliability. A private platform-as-a-service (PaaS) is a development and deployment platform that typically includes middleware, database, and development tools. A private infrastructure-as-a-service (IaaS) delivers computer infrastructure that is based on virtualization, server, and storage. For middleware, you can chose from the following products: Oracle FusionRedHat JBossIBM WebsphereTibco ActiveMatrixGlassFish You can use the following databases: Oracle DBMySQLPostgreSQLH2IBM DB2Microsoft SQL Server Virtualization products are listed below: VmwareOracle VirtualBoxMicrosoft Virtual PC We prefer to run applications on linux\/unix based servers. To provide monitoring and managing of your cloud, we prefer employing Enterprise Service Manager (ESM). ESM is capable of monitoring and managing all mission-critical infrastructure components such as applications, services, operating systems, network protocols, systems metrics, and network infrastructure.