Establishing a Connection
Protocol is a formal set of conventions governing the format and control of inputs and outputs between two communications devices. This includes the rules by which these two devices communicate as well as handshaking and line discipline
Handshaking is the exchange of predetermined signals when a connection is established between two data devices. This is used to establish the circuit and message path.
Session is the logical connection between two terminals. This is the part of the message transmission between two points after the communications circuit has been established and is functioning.
Store and Forward is a data communication technique that accepts messages or transactions, stores them, and then forwards them to the next location or person as addressed in the message header.