A form of communication that requires applications to run concurrently. A process issues a call and until it receives a response.

transmission of a block of characters at a time rather than one character at a time.

A communications system where the data is transmitted and received at discrete times, which are usually synchronized by a clock signal.

A method of transmission in which data bits are sent continuously at the same rate under the control of a fixed frequency clock signal.

Transmission method whereby a fixed frequency synchronizing clock signal is used to synchronize data sent between a sending and receiving device.

High-speed transmission of contiguous groups of characters in which the stream of monitored and read bits uses a clock rate to transfer the characters over a communication line.