In a communication system, data are propagated from one point to another by means of
electromagnetic signals. A signal is a series of analogue or digital data. That is a varying voltage
(either continuous or discrete) with time in an electronic communication system.
Definitions of Data and Signals:
Analog Data - Data represented by a continuous physical quantity whose magnitude is proportion
a suitable function of the data (information). It can have more than two discrete values in
contrast to digital data. ...