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Analog and digital are two different ways of describing quantity.

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If you ask a fisherman how many fish he has caught,

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and he holds up eight digits like this,

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he is describing the quantity of fish in a digital way.

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He's using separate individual digits to describe separate individual objects,

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which is fine, because this is a very clear-cut situation.

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You either catch eight fish or you don't.

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You can't catch a little less or a little more than eight fish.

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But if you ask the fisherman how big the fish was that got away,

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and he holds his hands up like this,

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he is describing the quantity of missing fish in an analog way.

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The distance between his hands is an analogy for the length of the fish.

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And this analog way of describing quantity

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is much more convenient than the digital way,

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when you have to describe something that can vary continuously,

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given the elastic nature of the average fisherman's memory. In the world of machines,

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one of the commonest analog devices is a dimmer. The turning of the knob corresponds to the fading

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up or down of the light. It is a continuously variable device. The light can be more or less

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on. Contrast this with a light switch, which is the simplest digital device of all. The light is

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either on or off. Which brings us to that collection of on-off switches which is called

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a computer. Obviously itself a digital device, since it has to deal with everything in terms

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of binary digits. The computer's keyboard is also digital. There are lots of separate

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individual keys, and you either press one or you don't. But this can be awkward when

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you have to describe something which varies continuously, such as the movement of a little

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rocket ship on the screen, because you have to fragment this movement into separate units,

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forward 30, right 90, forward 30, and so on. So here is where it's much better to use the

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analog way of representing continuous movement by means of game paddles, which relate directly

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to what is happening on the screen. The more you turn the paddle, the more the rocket ship

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turns. But there's room for both ways, of course, both analog and digital. If you

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want to represent reality in a smooth, continuous fashion, go analog. If you want

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to represent reality one little piece at a time, go digital.