Signal

• A signal is an electromagnetic or electrical current that is used for carrying data from one system or network to another.
• it refers to any time-varying voltage that is an electromagnetic wave that carries information.
• Analog Signal and Digital Signal are two types of signals that carry information.

Analog Signal

• Analog signals are continuous electrical signals.
• Its amplitude takes any value in a continuous range.
• They are continuous in nature which varies with respect to time.
• It is generally bound to a range of +12V to -12V, but there is an infinite number of values within that continuous range.
• It can be either periodic or non-periodic.
• It is Represented by sine waves
• Analog signals use more power.
• Analog hardware never offers flexible implementation.
• It requires components like Resistors, Capacitors, Inductors, and Diodes for analog circuits.
• Analog instruments give considerable observational errors.
• Processing can be done in real-time and consumes lesser bandwidth compared to a digital signal.
• Analog signals are suited for audio and video transmission.
• These signals are more prone to noise as they travel through the medium, these noises result in information loss in the signal.
• Troubleshooting analog signals is difficult.
• Analog to digital converter converts analog signal to digital signal by a process called Sampling and Quantization.
• The use of analog signals has been declined with the arrival of digital signals.
• Examples - Human voice, natural sound, analog electronic devices, Temperature sensors, FM radio signals, Photocells, Light sensors, Resistive touch screens are examples of Analog signals.

Digital Signal

• Digital signals are non-continuous electrical signals.
• Its amplitude takes only limited values.
• They are discrete in nature with respect to value and time.
• This signal contains only distinct values.
• Digital signals carry binary data (0 or 1) in form of bits.
• It can only contain one value at a period of time.
• It consists of different voltage values, the minimum value is 0 volts whereas the maximum value is 5 volts.
• It is represented by square waves.
• Digital signals use less power.
• Digital hardware offers flexibility in implementation.
• It requires components like transistors, logic gates, and micro-controllers for digital circuits.
• Digital instruments never cause any kind of observational errors.
• It never gives a guarantee that digital signal processing can be performed in real-time.
• Digital signals are suited for computing and digital electronics.
• Digital signals are stable and less prone to noise compared to analog signals.
• Troubleshooting of digital signals is easy.
• Transmission of digital data in the analog channel is done by a process called Modulation.
• Examples - Computers, optical drives, CDs, DVDs, Digital watches, Digital video signals, and other electronic devices.