Language family
A group of languages descended from a common ancestor.
Glottolog classifies the world’s languages into families on genealogical grounds — shared descent, established through historical-comparative work — and as of its current edition counts 246 families alongside 183 isolates.
Two cautions come from Glottolog itself. The classification is “the best guess by the Glottolog editors”, and “for many groups of languages, there is little available historical-comparative research, so the classifications are subject to change”. A family tree is a finding, not a fact.
This Atlas records a root (the top-level family) and, where useful, a leaf (the lowest branch a reader would recognise), collapsing everything between. Intermediate nodes are where classifications disagree most and help a reader least.