The meaning of unsigned

The above quote is from https://dev.mysql.com/doc/refman/8.0/en/arithmetic-functions.html
Could you, especially the meaning of the word unsigned here, rephrase it?

-1 : signed integer
+1 : signed integer
1 : unsigned integer

Thank you.

Basically an unsigned integer can never be negative, so the first bit of the number that is normally reserved to indicate if the number is negative or not can now be used for the number itself, meaning you will be able to represent larger numbers than with signed integers.

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From memory the big difference is the range for small integers:

  1. Signed is -127 to +127
  2. Unsigned 0 to 255
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I was just going to say that!

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What you’re describing is for TINYINT. It works for all kinds of integers though, as can be seen in da manual.

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