What is a signal? F(x) for distance Or F(t) for time is a signal. A signal is a function that represents the variation for physical quantity with respect to any parameter. F(x) = ax^2 - b^x +c For example. Straight line, parabola, etc. Y = mx + c Is also a function. Analog vs digital signal Consider the digital clock and analog clock. Consider the minute hand of analog clock. Digital means it has certain levels. Nothing can be between two levels. Analog means it can take any value. Discrete time signal- The signal defined for discrete intervals of time. Discrete time signal is a subset of analog signal Discreet signal . Time can take only discreet intervals but f(t) can take up any value. Analog signal Both time and function of time can take up any value. But, in digital signals, we make both time and f(t) discreet. Digital signal Both t and f(t) have discreet values. If we choose large discrete intervals for f(t) then we will...