Areal zones, linguistic areas of convergence or sprachbunds: they are areas that have different languages families but which, by prolonged contact, developed similar linguistc features, be it phonology or grammar.
Northwest America (uvulars, aspirated consonants, ejectives, glotalized consonants, polysyntetic languages,
Mesoamerican area (polysyntetic languages, uvulars, ejectives, rhotics, tones, nasal vowels, lateral fricatives)
Creole Caribbean (creole languages, analytical syntax)
The Andes region (highly agglutinative, uvulars, ejectives)
Standard Average Northwestern European (uvular rhotics, more analytic and fusional, obligatory subject pronouns/no null-subject, front rounded vowels)
North and Central Iberia (apical-alveolar sibilants and affricates, heavy verb conjugations, no b-v distinction)
The Balkans (definite articles as suffixes, simple vowel systems, romanian-slavic convergence)
The Caucasus (high number of phonemes, polysyntetic, ejectives, aspirates, retroflex consonants, ergativity)
Central and North Asia (correlated with Altaic) (SOV structure, vowel harmony, agglutination)
The Indian Subcontinent (retroflex plosives, split-ergativity, many cases and gendered classes or animated distinctions, vowel reduction)
China and Indochina (higly tonal languages, front rounded and back unrounded vowels, analytical syntax, few morphology)
Southern and Southwestern Africa (click consonants, simple noun class system)
Australian Aboriginal (no fricatives, no voicing distinction, many apical and retroflex distinctions, highly agglutinative)