Long Term Support (LTS) releases are as old as software. However, Canonical, the company behind Ubuntu, was the first to use the term, and now other open source projects, including the Linux kernel and many distributions, distinguish between LTS, regular, and rolling releases, each of which has different advantages and appeal to a different class of user.
Many users are content with regular releases every six to 18 months. Others who demand the very latest, prefer rolling releases, in which each package is updated whenever it is ready. By contrast, as the term implies, LTS releases are supported longer periods — typically, two to five years, although Canonical also offers Extended Security Maintenance as a paid service for another two years.
LTS releases are supported through their specified support duration by security updates, bug fixes, backports, and new device drivers, just like a regular release, although in some projects like Debian, they do not have point releases, which means that how and when fixes are applied can be different than in a regular release. Similarly, LTS releases may support only the most popular hardware architectures supported by regular releases.
Read more at The New Stack