Continuous-time and discrete-time systems
· Physically, a system is an interconnection of components, devices, etc., such as a computer or an aircraft or a power plant.
· Conceptually, a system can be viewed as a black box which takes in an input signal x(t) (or x[n]) and as a result generates an output signal y(t) (or (y[n]).
· A system is continuous-time (discrete-time) when its I/O signals are continuous-time (discrete-time).
