Computers only understand data, that data may be in the form of instruction, something to store for later, or as something to process.

When we interact with a computer in any form, we do it for data. A simple example of this is when we use a calculator, or calculator application. In this case, we enter a number an operator (+, -, /, *) and another number.

Some slightly more complicated examples could be to write or read an article where we transfer data from the writer to the reader, or when we watch a movie or play a game where someone added data in the form of images, sounds, or interactions for us to experience. The list goes on and includes anything we do to interact with a computer.

As a non-computer, we still mainly function on data. In fact, our ability to process data often puts computers to shame. We can take a few seemingly unrelated pieces of data and extrapolate wholly new concepts. While this is a fantastic ability, we often overuse this ability and ignore data that is available that would give us a more precise answer then we could come up without it.

Let me give you an obvious example. Take the following equations.

5 * 3 / (x + 2) = y

Now give me the value of y as a number. We obviously can't do that with any hope of a correct answer without knowing x. However, that is the kind of thing we can do much better than a computer. It will still be wrong but if it were on a multiple choice quiz in school we would still pick a number based on what kind of numbers x has been in previous questions and what seems like a reasonable answer at least has a chance of being right and so is better then a definite wrong answer.

When we are writing our code, we often make assumptions about how they will be used and don't take the time to figure out what x is.

Assumptions are unopened windows that foolish birds fly into, and their broken bodies are evidence gathered too late. - Bryan Davis

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