In Entity Framework Core, migration bundles are standalone executables that can be executed independently of the source code, offering minimal dependencies and flexibility in application deployment. They were introduced as a solution to address dependencies and provide a safer way to update databases with EF Core. Migration bundles offer several advantages, including being decoupled from the rest of the application, having minimal dependencies, and allowing for self-contained execution. By using migration bundles, developers can streamline the database migration process, ensuring smooth transitions in database schema evolution. The process involves generating a migration bundle, which includes the necessary database migrations, and then executing it to apply the changes to the database. This approach allows for a more controlled and efficient way of managing database updates, making it an attractive option for .NET developers working with EF Core.