Diaspora

Diaspora refers to ethnic populations dispersed from their homeland across the world, or the phenomenon itself. Originally describing Jews scattered after the Babylonian exile, the term applies more broadly in modern usage.

Major diasporas: Jewish (dispersed worldwide before the founding of Israel), Chinese/overseas Chinese (centered on Southeast Asia but present worldwide), Indian (widely present in the UK, USA, Middle East, and East Africa), Armenian (dispersed worldwide), Irish (settled largely in the USA).

When a country is described as having the world's largest diaspora, China (overseas Chinese) or India are the likely candidates. If the clue is that the population abroad far exceeds the population at home, Ireland or Armenia are strong candidates. Knowing about diasporas is also a key to understanding why the culture of a particular country has spread around the world.