With migrations, FuelPHP provides an easy way to manage database changes. It is typically used in combination with the oil utility to make changes to the database. Migrations are PHP files that push database changes in a versioned form. The generation of migration scripts is also simplified by the oil utility, which treats the name of the migration as an indicator of the activity to be performed, such as creating or renaming database tables.
Every migration script provides the ability to move up or move down a version so you do not have to keep multiple databases running to test your app across different versions of the database, at least in theory.