The Grid is the computing and data management infrastructure that will provide the electronic underpinning for a global society in business, government, research, science and entertainment [1][2][3][4][5]. Grids, illustrated in Figure 1.1, integrate networking, communication, computation and information to provide a virtual platform for computation and data management in the same way that the Internet integrates resources to form a virtual platform for information. The Grid is transforming science, business, health and society. In this book we consider the Grid in depth, describing its immense promise, potential and complexity from the perspective of the community of individuals working hard to make the Grid vision a reality.Grid infrastructure will provide us with the ability to dynamically link together resources as an ensemble to support the execution of large-scale, resource-intensive, and distributed applications.Grid Computing -Making the Global Infrastructure a Reality.