In telecommunications and computing, a data stream is a sequence of digitally encoded coherent signals (packets of data or data packets) used to transmit or receive information that is in the process of being transmitted.[1]
In electronics and computer architecture, a data flow determines for which time which data item is scheduled to enter or leave which port of a systolic array, a Reconfigurable Data Path Array or similar pipe network, or other processing unit or block (cf. main article).
Often the data stream is seen as the counterpart of an instruction stream, since the von Neumann machine is instruction-stream-driven, whereas its counterpart, the Anti machine, is data stream driven.
The term "data stream" has many more meanings, such as by the definition from the context of systolic arrays.
Formal definition
In a formal way, a data stream is any ordered pair 
where:
is a sequence of tuples and
is a sequence of positive real time intervals.
References
