Versioning
I'm a strong believer in putting a version on everything I produce. There are a couple of reasons, but the main reason is because I want to be able to look at a copy I gave someone or flip to the legal page of a book and see if anything is missing. In one case, I accidentally gave a reviewer an older copy (not that it would have changed things) and didn't realize it until after the point (that was one of the reasons I version as I do).
I use a versioning convention called Semantic Versioning which describes how to parse or understand the version. In this system, a version consists of three numbers separated by periods, such as “1.2.3”. Even in writing, using this convention makes sense.
The first number, the major version, describes major breaking changes. This would be things like Guido shooting first in Star Wars or rewriting the chapter to use modern technology instead of dated one. I don't believe there should be any judgement when an author chooses to do this, but it should be clear that a major, plot-breaking change was made.
The second number, the minor, is when you add to the story. Maybe you add a paragraph to clarify a confusing point or add a chapter to add some flavor or set the scene. The main point is that a minor version change means that the story is still intact, it just has something more.
The third, patch, is for fixes. This is typos, missing periods, and the little changes. It should only be used for those frustrating little that show up only after you get corrections from Amazon Kindle or a kind reader points out you changed someone's eye color in chapter four.
One thing to point out is that you can easily have larger numbers in the middle. I've had a story that hit a version tha looked like “1.13.1”.
Comparing Versions
To see if one version is greater than the other, you compare the numbers from left to right. For example, look at the major version. Version “2.0.0” is more recent than “1.98.12”. If the numbers are the same, look at the second and do the same, then the patch.
Versioning Styles
I prefer an approach called conventional commits to figure out my versions. This is based on the commits messages and calculates the version automatically based on what is changed. I find it easier since it means every change bumped up the version and I don't have to worry about accidentally have two different copies that are both “version two.”
The opposite of a semantic version is a romantic version. This is when the author decides the story has reached a new version and manually changes it. It is “romantic” because it is based on the subjective feelings of the creator.