WHAT MAKES SOMETHING ‘DIGITAL’ – MY MOBILE & TV ARE, BUT IS MY FAX, MY WASHING MACHINE, AND IF NOT, WHY NOT?

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Digital refers to the electronic circuitry used to run the stuff. A digital circuit runs in one of two states: on or off, or high or low, or 1 or 0, or voltage or no voltage it all means the same thing. There are many, many transistors inside chips in “digital” circuitry. These transistors react to a voltage present or no voltage present, usually 5 volts or 0 volts. Thats all they run on. So they react to this and nothing else. Thats where the 0 and 1 come in, or on or off, high or low. The chips in a “digital” circuit interact with each other using this language, this two-state language of 0 and 1.
Thats digital.

What isn’t digital is referred to as “analog”. There are no computer chips present, and no common 0 and 1 states of voltage are used. Its just different types of components.

Take a car for example. An older car will have within its electic circuitry light bulbs, a starter motor, small electric motors for such things as the windshield wipers and power steering. Everything will have relays and switches to tell it when to turn on and off. Nothing digital there.

Take a newer car. It will still have the same light bulbs, starter motor, etc… But instead of a few relays being used for a few things like telling the blinker to blink like on an older car, within the circuit is chips with thousands of transistors working as thousands, even millions of relays. And these little relays work and react to each other in one way: by turning off and on when its told to by others little relays being told to turn off and on. Remember: off and on is the same as voltage and no voltage, 0 and 1, low and high. These two states alone are in the circuit and all these little relays are turning each other off and on at an incredible speed. And when these do this, they can be set up to do incredible things, like make the fuel/air mixture a perfect blend, turn on the lights by themselves when it gets dark enough, and make the all kinds of things happen that a car without “digital” technology could never do.

So to put it a different way, “digital” means there is what most people refer to as computer chips within the circuit. Something that isn’t digital, or otherwise referred to as “analog” is something that doesn’t have computer chips in it.

the term “digital” refers to the two states (off and on, like a light switch) that are used in the circuit, commonly represented by 0 and 1. You have the two numbers, or digits 0 & 1, hence the term “digital”.