There are no crisp definitions of Grids [1, 2] and Peer-to-Peer (P2P) Networks [3] that allow us to unambiguously discuss their differences and similarities and what it means to integrate them. However, these two concepts conjure up stereotype images that can be compared. Taking ‘extreme’ cases, Grids are exemplified by the infrastructure used to allow seamless access to supercomputers and their datasets. P2P technology is exemplified by Napster and Gnutella, which can enable ad hoc communities of low-end clients to advertise and access the files on the communal computers | 18 Peer-to-peer Grids Geoffrey Fox 1 Dennis Gannon 1 Sung-Hoon Ko 1 Sangmi-Lee 1 3 Shrideep Pallickara 1 Marlon Pierce 1 Xiaohong Qiu 1 2 Xi Rao 1 Ahmet Uyar 1 2 Minjun Wang 1 2 and Wenjun Wu1 Indiana University Bloomington Indiana United States 2Syracuse University Syracuse New York United States 3Florida State University Tallahassee Florida United States PEER-TO-PEER GRIDS There are no crisp definitions of Grids 1 2 and Peer-to-Peer P2P Networks 3 that allow us to unambiguously discuss their differences and similarities and what it means to integrate them. However these two concepts conjure up stereotype images that can be compared. Taking extreme cases Grids are exemplified by the infrastructure used to allow seamless access to supercomputers and their datasets. P2P technology is exemplified by Napster and Gnutella which can enable ad hoc communities of low-end clients to advertise and access the files on the communal computers. Each of these examples offers services but they differ in their functionality and style of implementation. The P2P example could involve services to set up and join peer groups to browse and access files on a peer or possibly to advertise one s interest in a particular file. The classic grid could support job submittal and status services and access to sophisticated data management systems. Grid Computing - Making the Global Infrastructure a Reality. Edited by F. Berman A. Hey and G. Fox 2003 John Wiley Sons Ltd ISBN 0-470-85319-0 472 GEOFFREY FOX ETAL. Grids typically have structured robust security services while P2P networks can exhibit more intuitive trust mechanisms reminiscent of the real world . Again Grids typically offer robust services that scale well in preexisting hierarchically arranged organizations P2P networks are often used when a best-effort service is needed in a dynamic poorly structured community. If one needs a particular hot digital recording it is not necessary to locate all sources of this a P2P network .