Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes. It is a system where the exchange of services takes place directly between the nodes. Client/Server is a distributed system where server is a high processing computer and client can be high or low processing computer. Server is the single point of failure and if server fails, whole system fails. Services to the clients are stopped. Server requires administration I.e. one has to control the functioning of server in order to serve other clients.Resources of clients cannot be used, so itís a resource wastage.SO these were some of the limitations of client/server which P2P tries to overcome.It connect different networks together,each network has a super node that keeps the information of all the shared file by the nodes in that network.Structured P2P follows some particular structure for file placements and query searching which is based on DHT(Distributed Hash Tables).