When the Internet is depicted in a flow chart it is usually represented by the outline of a cloud. This metaphor is now being used to describe a new generation of cloud computer services that are delivered over public and private networks. These services can include software, data storage, and data processing. Traditionally, users have accessed these services from their own computer or on a specific machine accessed over a network connection. In most cases, these services were purchased as products. Software is sold, and storage and processing hardware are purchased and operated by individuals, corporations, or governments. In other instances, software is licensed, and computer resources can be rented from hosting companies based on the hardware specification and geographic location.
Cloud computing differs from these conventional approaches by offering all of these products as a service. When cloud computing services are delivered, the user does not necessarily know the type of hardware used or the location of the data center. All services are delivered in an opaque fashion over a network connection. In fact, the services may be delivered from many computers spread across multiple data centers in order to balance loads and provide redundancy. The end user requires minimal hardware and software resources in order to access cloud computing services.
Cloud Computing services can be delivered to individuals or to large corporate or government entities. For example, individual services such as Google Docs or Facebook which are offered free of charge. Corporate applications that are delivered by cloud computing include Amazon’s web hosting solutions and Salesforce.com’s application delivery.
When supplied to a corporate or government entity, cloud computing services are provided based on the client’s consumption so there is no need to make a large, up-front investment. Organizations are freed from the requirements of owning and operating the hardware and software required to provide needed services as well as the associated personnel and overhead. By storing data on a network, individual users and large organizations no longer need to maintain storage on their computers, laptops, or mobile devices. This model eliminates the possibility of data being lost due to stolen or misplaced devices. Cloud hosted applications also require less memory and storage on the user’s computer and can even consume less energy. Finally, the distributed nature of cloud computing ensures equal access to applications, data, and processing resources from any location with access to the Internet.
When an individual or a corporation decides to utilize cloud computing resources they are trading control for simplicity. With their applications and data being hosted on computers in unknown locations, they have to trust that their provider will ensure the required performance, reliability, and security. Some individuals and organizations are reluctant to surrender control of the hardware and software used to access their most important applications and data.