how would you define the word "digital"?

Question

based on the differences of an analog & digital clock.

Answer 1

Electronic circuits that function based on whether an electrical current is on or off are digital. Current On or currrent that has reached an arbitrary level of amperage, is usually defined as 1; and Current Off, or current that is below an arbitrary level of amperage, is usually defined as 0. Hence the term "digital".

Electric curcuits that function based on the strength of the current (such as a dimmer switch that make a light bulb brighter or dimmer) are analog.

To use the analogy of a digital vs. analog clock:

On a digital clock the display stays at "12:00" for one full minute, until the time reaches the next discreet level of 12:01. 12:00 and 59 seconds is still displayed as "12:00".

On an analog clock the minute hand slowly sweeps across the face of the clock from 12:00 to 12:01, passing through and displaying all of the infinitessimal time gradations in between the minute marks.
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Answer 2

analog signals are continuous
discrete signals have only specific defined values (such as high and low voltages used in digital logic -- although much more could be said about that based on the operation of transistors since there is more of a fundamental "analog-ness")
a digital signal is a coded discrete signal, i.e. the stream of data from a discrete signal is to be interpreted in a particular manner.

how do we apply this to analog and digital clocks?

in an analog clock, you typically have a "motor" that spins continuously to rotate the hands. the accuracy of the clock therefore depends on that motor spinning at the same speed. in some electric clocks, that "motor" is an actual electric motor that depends on the frequency of the AC power line. in a wind-up watch, the tension of a spring is used to drive the miniature gear system, so keeping the watch well wound helps with the accuracy. and because there are moving parts, friction between those parts also affects accuracy.

in a digital clock, pulses are counted -- this is the discrete signal part. the count of those pulses are "translated" to display the numbers to indicate the time -- this is the "coding" part that makes it digital and not merely discrete. the accuracy of digital timepieces depends on a steady stream of pulses at a regular rate. such pulses are typically generated from a quartz crystal, such that a stream of many thousands of pulses per second are counted. this, and the fact that there are no moving parts makes for greater accuracy.

Answer 3

An analog clock gives a continuously variable readout. The digital clock gives a specific, discreet readout.

Hope that helps.

Answer 4

"digital" - to count. Digital systems/circuits count "1"s and "0"s.

Analog - continuous. Analog systems/circuits handle continuously changing signals which are as a million shades of grey.

Answer 5

Digital is everything that works with eletricity or part with it handling some information.