ELECTRONICS : the branch of engineering which deals with current conduction through a vacuum or gas or semiconductor is known as electronic. ANALOG SIGNAL: A continuously varying signal (voltage or current) is called an analog signal For example: sinusoidal voltage . Digital signal : A signal which can have only two discrete values is called a digital signal. For example a square wave is a digital signal. 0 Digital circuit : An electronic circuit that handles only a digital signal is called a digital circuit.
