Migrations mean a lot of things in software, but they usually entail some sort of important change.
- A data migration is when you move data from one database to another, usually to save money or get better performance
- A schema migration is when you update the schema in your database, and need to apply those changes to your data
- An infrastructure migration might mean moving your app from one type or server to another, or one type of architecture to another
Though schema migrations are pretty run of the mill, the other two types are generally huge, risky deals that instill fear in the minds of even the most savvy developers.