Migration is the movement of either people or animals from one area to another. Look up in the trees, where you might see a Monarch butterfly make a stop on its migration to Mexico.
Migration can be used for the journey from one place to another or for the act of movement. Thousands of mid-western farmers made the migration to California during the dust bowl. Demographers have noted the migration of young people to the big cities presumably for work. With animals, it’s almost always in reference to a seasonal change in location. On boat tours, you can see the whales during their annual migration down the West coast.