The most common description of Grid computing includes an analogy to a power grid. When you plug an appliance or other object requiring electrical power into a receptacle, you expect that there is power of the correct voltage available, but the actual source of that power is not known. Your local utility company provides the interface into a complex network of generators and power sources and provides you with (in most cases) an acceptable quality of service for your energy demands. Rather than each house or neighborhood having to obtain and maintain its own generator of electricity, the power grid infrastructure provides a virtual generator. The generator is highly reliable and adapts to the power needs of the consumers based on their demand.

The vision of Grid computing is similar. Once the proper kind of infrastructure is in place, a user will have access to a virtual computer that is reliable and adaptable to the user's needs. This virtual computer will consist of many diverse computing resources. But these individual resources will not be visible to the user, just as the consumer of electric power is unaware of how their electricity is being generated. To reach this vision, there must be standards for Grid computing that will allow a secure and robust infrastructure to be built. Standards such as the Open Grid Services Architecture (OGSA) and tools such as those provided by the Globus Toolkit provide the necessary framework. Initially, businesses will build their own infrastructures (what we might call intra-grids), but over time, these grids will become interconnected. This interconnection will be made possible by standards such as OGSA and the analogy of Grid computing to the power grid will become real.

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