Currently, most P2P systems work on wired Internet, which depends on application layer connections among peers, forming an application layer overlay network. In MANET, overlay is also formed dynamically via connections among peers, but without requiring any wired infrastructure. So the major differences between P2P and MANET that concern us in this article are: a. P2P is generally referred to the application layer, but MANET is generally referred to the network layer, which is a lower layer concerning network access issues. Thus, the immediate result of this layer partition reflects the difference of the packet transmission methods between P2P and MANET: the P2P overlay is a unicast network with virtual broadcast consisting of numerous single unicast packets, while the MANET overlay always performs physical broadcasting.b. Peers in P2P overlay are usually referred to static node though no priori knowledge of arriving and departing is assumed, but peers in MANET are usually referred to mobile node since connections are usually constrained by physical factors like limited battery energy, band-width, computing power, and so forth.