Is there an explanation why NodeJS latest version is 6.2.1 but the LTS is 4.4.5? It might seem odd but shouldn't they stabilized version 5 first before working on or releasing version 6?
The reasoning behind this is that Node works to a 'LTS schedule':
x.y.z) are created from the master branch every six months - even-numbered releases in April, odd-numbered releases in October.
If it helps you visualize it, there's a diagram of the schedule on the Node LTS GitHub:
This allows there to be a predictable release schedule and migration path for those who have to support their Node infrastructure long-term, while keeping the pace of development moving for those who want to stay on the cutting-edge of new features. Bear in mind that under SemVer (the versioning scheme that Node uses), breaking changes are only allowed in major-version releases - having a regular schedule for these coming out ensures that these changes can be tested before they get added to an LTS version further down the line.
For more info, I recommend taking a look at the Node LTS GitHub - this is where I got all this information from, and it's a pretty helpful resource.