Released last year in February, KDE Plasma 5.18 is the current LTS branch of the popular desktop environment used by numerous GNU/Linux distribution. 5.18 is supported with maintenance updates for about one and a half years after its initial release.
Some distros prefer to stick to an LTS branch of a major software as it is supposed to offer better stability and reliability. KDE Plasma 5.18.7 LTS is here six months after the previous update, KDE Plasma 5.18.6, and brings a handful of bug fixes.