A signal is defined as any physical quantity that varies with time, space or any other independent variable or variables. It may be a function of one or more independent variables. The signal itself carries some kind of information available for observation.
Usually signals are classified into two typesSignals
Analog signals Discrete signals
(Continuous signals) ( Dis –continuous signals)
ANALOG SIGNALS: - The analog signals are continuous function of an independent variable such as time, space etc.
DISCRETE SIGNALS: -
A discrete signal is a function of a discrete independent variable, which is an integer. A digital signal is same as discrete signal except that the magnitude of the signal is quantized.