No, they're not "sub versions", they are separate versions.
7.0.0 is one distinct version. 7.0.1 is the next version. 7.0.2 next, and so-on. These numbers are usually talked about in terms of "major", "minor" and "point" releases.
A major release usually represents a massive structural change (or a major rebranding exercise in some software). A minor release is usually some improvements, new functionality and often changes to existing functions. A point release is very rarely anything more than bug fixes or minor enhancements that don't change the shape of the database or functionality.
As a general rule, you should choose the latest point release for the major.minor version you choose.
In your case, you should upgrade to 7.0.latest, then, as that's out of support, make a choice to go to 7.4 or 7.5 (again, use the latest point release)
Hey Community mates! Claire here from the Software Product Marketing team. We all know software development changes rapidly, and it's often tough to keep up. But from our research, we've found the h...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs