Web services are a new breed of Web application. They are self-contained, self-describing, modular applications thay can be published, located, and invoked across the web. Web services perform functions, which can be anything from simple requests to complicated business processes … Once a web service is deployed, other applications (and other web services) can discover and invoke the deployed service
IBM Web Service Tutorial
A computer network protocol definies a format and order of messages sent and recieved among network entities, and actions taken on message transmission and reciept.
In a peer to peer (P2P) network every machine can communicate directly with every other machine in a network. No computers have any more authority than others. This is in direct contrast to client-server architecture.
A peer-to-peer (or P2P) computer network uses diverse connectivity between participants in a network and the cumulative bandwidth of network participants rather than conventional centralized resources where a relatively low number of servers provide the core value to a service or application.
The application layers provides applications with access to the communications environment. A network-enabled application will create a user interface as well as interfacing with application layer network protocols.
“A network is a system or group of interconnected elements. A computer network is a group of computers and peripherals connected together to communicate with each other and to share information and resources.”
http://www.micro2000.co.uk/network_glossary.htm