Continuous-Time Signals

Analog signals are continuous in time.

A continuous-time signal is an infinite and uncountable sequence of numbers, as are the possible values each number can have.

• between a start and end time, there are infinite possible values for time $t$ and the waveform's instantaneous amplitude $x(t)$.

A continuous signal cannot be stored, or processed, in a computer since it would require infinite data.

Analog signals must be discretized (digitized) to produce a finite set of numbers for computer use.