Infrastructure: This is the basic physical and organizational structures needed for a society or enterprise. For example roads, bridges and ports are all part of a country's infrastructure.
Trade Routes: These are specific paths used for trading goods between cities, regions or countries. Famous historical trade routes include the Silk Road and Trans-Saharan route.
Migration: This refers to the movement of people from one place to another with intentions of settling temporarily or permanently in the new location. It can be within a country (internal migration) or between countries (international migration).