Create distortion from basic linear (and non-linear if neccessary) DSP elements

1. What is the difference between linear and nonlinear distortion?
2. Which method induces non-linear distortion between analog and digital frequencies?
3. What are the different types of distortions in linear systems?
4. What is linear and nonlinear in signal and system?

What is the difference between linear and nonlinear distortion?

A linear distortion is defined as a change in amplitude or phase with no new frequencies added. A non-linear distortion occurs when new frequency components are generated. Non-linear distortions are what is usually meant by "distortion".

Which method induces non-linear distortion between analog and digital frequencies?

Quantising distortion is introduced by analogue to digital coding techniques where an input signal is sampled and encoded into a finite set of values. The quantising distortion results from the difference between the recovered analogue signal.

What are the different types of distortions in linear systems?

Consequently the distortions of linear systems are divided into two categories: amplitude and phase distortions.

What is linear and nonlinear in signal and system?

A system that multiplies the input signal by a constant, is linear. This system is an amplifier or an attenuator, depending if the constant is greater or less than one, respectively. In contrast, multiplying a signal by another signal is nonlinear.