Which statement best captures the difference between digital and analog signals?

• A. Digital uses discrete values; Analog uses continuous values
• B. Digital uses continuous values; Analog uses discrete values
• C. Both use discrete values
• D. Digital uses only negative values

Answer: (A)

Signals differ in how their values change over time. Digital signals use discrete values, stepping between a finite set of levels (often 0 and 1). Analog signals vary continuously, so their amplitude can take any value within a range and the waveform is smooth. This matters because discrete values make digital systems easier to store, transmit, and reproduce reliably in the presence of noise, while analog signals capture fine variations but are more susceptible to distortion from noise. An everyday analogue example is the voltage from a microphone, while a digital example is the sequence of bits that represents audio in a digital file. So, digital uses discrete values; analog uses continuous values.