<P> In telecommunication , a communication protocol is a system of rules that allow two or more entities of a communications system to transmit information via any kind of variation of a physical quantity . The protocol defines the rules syntax , semantics and synchronization of communication and possible error recovery methods . Protocols may be implemented by hardware , software , or a combination of both . </P>
what aspects of network communication are described by a protocol
the rules syntax , semantics and synchronization of communication possible error recovery methods