Learn in the textbookApplying Virtualization and System Usage/Operation Modes
DefinitionMigration (マイグレーション) means moving a system, data, a virtual machine, or similar from its current environment to another one.
ExplanationSwitching from an old server to a new one, or moving in-house servers to the cloud, are examples. In virtualization, moving a virtual machine to another physical server is also called migration. The word does not limit how the move is done and broadly covers the act of moving itself.
AnalogyIt is like moving house. You carry your belongings from the current home to the new one so you can go on living the same way there.
Memory hookTo migrate is for people or animals to move where they live, as birds do each season. The image behind the word is changing one's home.