Numerical Representations

Physical systems use quantities which must be measured, monitored, recorded, manipulated arithmetically. Quantities may be represented numerically in two form.

• Analog Form.
• Digital Form.

Analog Representation

Analog Representation is a continuously variable, proportional indicator. Here is some example-

• Sound through a microphone causes voltage changes. Like as-
• Automobile speedometer changes with speed.
• Mercury thermometer varies over a range of values with temperature.
  

Digital Representation

Digital Representation is varies in discrete (separate) steps. Here is some example-

• Passing time is shown as a change in the display on a digital clock at one minute intervals.
• A change in temperature is shown on a digital display only when the temperature changes at least one degree.

Digital System

Digital system is a combination of devices that manipulate values represented in digital form. 

• Mostly electronic devices, also included mechanical, magnetic or pneumatic.
• Familiar digital systems include digital computers, calculator, digital audio & video equipment, and telephone system etc.

Analog System

Analog system is a combination of devices that manipulate values represented in analog form.

• Amplitude of the output signal to the speaker in a radio receiver can have any value between zero and its maximum limit.
• Common analog systems are audio amplifiers, magnetic tape recording and playback equipment and a simple light dimmer switch.

Advantages of Digital Techniques

Digital Techniques has hugs amount of facilities to use. Like as- 

• Ease of design
• Well suited for storing information
• Accuracy and precision are easier to maintain
• Programmable operation
• Less affected by noise
• Ease of fabrication on IC chips

Limitation of Digital Techniques

There is also some limitations of digital techniques also- 

• Real world is analog.
• Processing digitized signals takes time.
• 4-steps followed when dealing with analog inputs & outputs
• Convert physical variable to an electrical signal (analog).
• Convert electrical signal (analog) into digital form.
• Process (operate on) digital information.
• Convert digital outputs back to real-world analog form.