Write a short note on peer-to-peer computing.

Peer-to-peer (P2P) system model is a kind of distributed OS. In this model, clients and servers aren't distinguished from one another. in its place, all nodes inside the system are considered peers, and each may proceed as either a client or a server, depending on whether it is providing or requesting a service. Peer-to-peer systems offer a benefit over traditional client server systems; several nodes distributed during the network can provide services.

To participate in a peer-to-peer system a node has to first join the network of peers. Formerly a node has joined the network, it able to begin providing the services to and requesting services from - other nodes in the network. Determining what services are available is proficient in one of two general ways:

 *  When a node connects a network it registers its service with a centralized lookup   service on the network. Any node wants a specific service first contacts this centralized lookup service to determine which node provides the service. The remainder of the communication takes among the client and the service provider.

**  A peer acting like a client must first discover what node provides a desired service by broadcasting a request for the service to all other nodes in the network. The node (or nodes) offers that service responds to the peer making the request. To favor this approach, a discovery protocol should be provided that allows peers to discover services provided by other peers in the network.