Physical processes of migration, in historical context
Human migration means human movement, and human movement requires means of travel and routes that can be followed. Except for hunter-gatherer or herding societies, in which migration is an inherent and defining element of everyday life, migrating humans also require special arrangements for food, clothing and shelter while traveling, and protection from human and natural hazards enroute. Mass migration of recent centuries has typically also entailed communication channels between the source and destination of the movement, acting to inform migrants, and for the logistical deployment of the transportation system used for the migration.
Examples and details, see links to left.