A more thorough explanation:

Definition: Movement (of people or animals) from one country or region to another.

Examples:

• People moving from Mexico to the United States for better job opportunities.
• Birds flying south for the winter to escape the cold weather.
• Salmon swimming upstream to spawn in their birthplace.

The examples illustrate the definition of migration by showing how different species move from one place to another for various reasons. People may migrate to find better living conditions or job opportunities, while animals may migrate to find better food sources or to reproduce. Migration is a natural process that occurs in many different forms throughout the world.