They are compared when you say

use Some::Module 6.41;
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See use for documentation, especially

If the VERSION argument is present between Module and LIST, then the use will call the VERSION method in class Module with the given version as an argument:

        use Module 12.34;
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is equivalent to:

        BEGIN { require Module; Module->VERSION(12.34) }
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The default VERSION method, inherited from the UNIVERSAL class, croaks if the given version is larger than the value of the variable $Module::VERSION .

> Also, when is the thumb rule for creating new versions?

See Semantic Versioning for one of the possible strategies.

> If I fix a typo in a comment, should I increment the version number?

Of course. CPAN/PAUSE would reject an upload with an existing version.

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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Also, when is the thumb rule for creating new versions? If I fix a typo in a comment, should I increment the version number? I'm guessing no. But when should I?

You should definitely increment the version number on every release, as many things will depend on that (CPAN, users of your module that require a specific version, and the general confusion that comes from having two different releases with no good way of keeping them apart). Then, consider whether you need to make a release if all you did is change a code comment.

Things are of course different for modules that are just for internal consumption, in that case the only person the version numbers will have an importance for is you, and you can do things as you like. But since keeping good version numbering is important for any code that goes beyond yourself, it's a good habit to get into.

Yeah, right now I'm just writing modules for myself. But I want to learn good habits in case I ever go "big time" and release a module for CPAN. It's kind of a little dream of mine. :)

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