When we release a new version, it is usually a major version of the software - Kentico 10, 11, 12, 13....However, as each software, there are also bugs. So, we try to fix them within 7-days and we are releasing hotfixes, which are fixing the issues. So, after you apply the hotfix, you will get a minor version number like 11.0.35 - where 35 is the number of the hotfix. This can tell us what bugs were already fixed and what not. This is very helpful in many cases.