Migration

noun

1. An instance of moving to live in another place for a while.
2. Seasonal moving of animals, as mammals, birds or fish, especially between breeding and non-breeding areas.
3. Movement in general.

   "The migration of lead from a can to the food inside it can cause lead poisoning."

4. Instance of changing a platform from an environment to another one.
5. The movement of cells in particular directions to specific locations.