Signal forms

• Analogue
  • Continuous-time signal
    Well-defined value at every point in the time interval of interest
  • Discrete-time signal
    Values only at discrete time instances
  • Sampled-and-held (S/H) signal
    Continuous signal whose values changes only at discrete-time instances
    
    

    

• Digital
  • Discrete-time signal or
  • Sampled-and-held (S/H) signal
    Values of signal can assume only discrete values