In this official Android source page (https://source.android.com/setup/start/build-numbers) that contains the code names, API levels and versions numbers some of the versions contain the character x in its version number for example:
So what does x character represents in the version numbers?
I believe that the "x" stands for all the versions for the specified version. For example, 2.2.x stands for 2.2.1, 2.2.2, and 2.2.3.
It is the API coverage.
As an example: Honeycomb Versions start from 3.0 to 3.2.6.
3.0 API 11
3.1 API 12, NDK6
3.2.x means that all versions starts with 3.2 are API 13. Also x is the patch level of API 13 for honeycomb.
In my opinion, X is mean all of something. Like 3.0.x mean all of 3.0.1,3.0.2,etc. And new version update of android studio, we got. androidX. I guess its mean, They put all feature of pre version in one.
The X in the Version Number suggests the Patch Update version. The First number stands for the Android Version Start (i.e 3 for HoneyComb and moving forward), the Second Number stands for the Sub-Android Version of the Base Version(i.e. 3.1) and the X then stands for the Patch Update Number(3.1.1).
