cessed and transported in minutes, on the fly, rather than over hours or days as is the present practice, is at the heart of the process of search and discov- ery for new scientific knowledge. Caltech's FAST protocol shows that the high degree of transparency and performance of networks, assumed implicitly by Grid systems, can be achieved in practice. THE INTERNET RULES-IP TECHNOLOGIES This will drive scientific discovery and utilize the world's growing band- width capacity much more efficiently than has been possible until now. 5.3 GRID COMPUTING Grid computing enables the virtualization of distributed computing and data resources such as processing, network bandwidth, and storage capacity to create a single system image, giving users and applications seamless access to vast IT capabilities. Just as an Internet user views a unified instance of content via the Web, a grid user essentially sees a single, large virtual computer. At its core, grid computing is based on an open set of standards and pro- tocols-such as the Open Grid Services Architecture (OGSA)-that enable communication across heterogeneous, geographically dispersed environments. With grid computing, organizations can optimize computing and data resources, pool them for large-capacity workloads, share them across net- works, and enable collaboration. In fact, grid can be seen as the latest and most complete evolution of more familiar developments-such as distributed computing, the Web, peer-to-peer computing, and virtualization technologies. Like the Web, grid computing keeps complexity hidden: multiple users enjoy a single, unified experience. Unlike the Web, which mainly enables communication, grid computing enables full collaboration toward common business goals. Like peer-to-peer, grid computing allows users to share files. Unlike peer- to-peer, grid computing allows many-to-many sharing-not only files but other resources as well. Like clusters and distributed computing, grids bring com- puting resources together. Unlike clusters and distributed c