What decides an ubuntu version to be LTS or non-LTS?

Question

I was wondering which factors decide an Ubuntu version to be LTS or non-LTS?

Answer 1

Ubuntu releases are time-based, that means they follow a schedule of releasing every April and every October:

• What's the difference between a Long Term Support Release and a Normal Release?

So far, every 2 years in the Spring is an LTS release. At some point that's just the cadence we fell into and since an LTS is an important release being able to tell people and partners that "the next LTS is in April 2014" becomes a real nice thing to have.

Now they just come every 2 years.

See also Eric's answer.

Answer 2

https://wiki.ubuntu.com/LTS

A new LTS version is released every 2 years. In previous releases, a Long Term Support (LTS) version had 3 years support on Ubuntu (Desktop) and 5 years on Ubuntu Server. Starting with Ubuntu 12.04 LTS, both versions will receive 5 years support. There is no extra fee for the LTS version; we make our very best work available to everyone on the same free terms. Upgrades to new versions of Ubuntu are and always will be free of charge.