Most humans, throughout most of human history, died close to where they were born. Exceptions, on a mass scale, are always noteworthy — people migrate for reasons of famine, war, religious persecution, and climate change. Though modern transportation may have made migration easier, the reasons remain noteworthy, and we have chosen migration as a topic to explore these deeper underlying forces.
How Wikipedia around the World defines Migration (add your language)
English: Human migration denotes any movement by humans from one district to another, sometimes over long distances or in large groups.
Spanish: Migration denotes any population displacement that occurs from a place of origin and destination to another involves a change of habitual residence in the case of individuals or habitat for animal species.
German: For geographers, historians and social scientists spatial mobility is a change in the position of an individuum between different entities of a spatial system.