Some websites say the latest version of X.org is 7.4, some say 11, and some say 1.15.1. These numbers are completely different from each other, yet it's the same version. Can anyone explain which number means what and why when installing drivers it says install on x.org 6.9 or later but after installing it says I have 1.15?
My guess is you are confusing Xorg numbering and the numbering of the modules.
If that does not clarify your version numbers, update your question with version of Ubuntu and the specific packages you are asking about.