Systems are comprised of compnents which together run the system. Signals are a form of energy, whose modulation affects the information contained in it.

Signals go through 6 basic stages: Input,Input detector, signal conditioning service,A/D and vice versa conversion, and display/control element.

Analog Signals are continuous whereas the digital signals are not.

The Nyquist theorem must be followed for sampling an analog signal otherwise Aliasing will occur.