Purpose of product- versus the target- and fixed-in-version?

[Jaap]

Purpose of product- versus the target- and fixed-in-version?

When we look at URL: https://www.mantisbt.org/bugs/view.php?id=11802 , we see:
Product Version 1.2.0
Target Version 1.3.0-beta.1
Fixed in Version 1.3.0-beta.1

Within the Issue-notes we see that the Target version might change.
At the end the issue its target will be equal to the "Fixed_in_version".

- What are the definitions of these three versions and how/when to use them?
- How will a correct project-(release)-version concept look like?
- What are possible scenarios, like:
- Short term issue all three versions might be the same.

I saw different usage of these versions, so let us try to clarify this ..
Some people use Product version only for a reported Bug, while others are using it in User-story/Feature too!

When introducing Agile then you want to have clear definitions of this terminology and how it is implemented within MantisBT.
I want to avoid fixing -afterwards, just due to the cause of misunderstanding the logic.

So what would be the best practice of these versions in Mantis Bug Tracker.

Cheers,
Jaap