“…Most of the methods in resource discovery tend to peer to peer (Al-Dmour & Teahan, 2005;Ali et al, 2005;Basu et al, 2005;Bharambe et al, 2004;Cai & Hwang, 2007;Iamnitchi et al, 2002;Koo et al, 2006;Nejdl et al, 2002;Oppenheimer et al, 2004;Shen, 2009;Talia et al, 2006;Zerfiridis & Karatza, 2003) which for example use super-peer (Mastroianni et al, 2005) or hierarchical (Liu et al, 2006) models. Apart from similarities between grid and peer to peer systems (Iamnitchi & Talia, 2005), they have critical differences in the field of security, users, applications, scale and etc.…”