Windows 10 distinguishes between a "Basic" language pack (just text) and a "Full" language pack (includes handwriting, speech, and optical character recognition).
The “v1.5” designation signifies the third major iteration of this community-driven installer script. Compared to v1.0 and v1.2, version 1.5 offers: Windows 10 Offline Language Packages Installer v1.5 -v1903