It can decouple you from the specific database implementation. The ORM can generate SQL that targets the database you are using by altering the generated querie

It can decouple you from the specific database implementation. The ORM can generate SQL that targets the database you are using by altering the generated queries to account for dialect and feature differences. For example, it can, potentially, make it possible to switch your application from using MySQL to PostgreSQL rather seamlessly. However, in my experience, this is rarely straightforward, and rarely done. It's not unusual for the application layer to become dependent on some quirk or unique feature of the underlying database, and sometimes that dependency is not obvious. The sibling reply is not far off the mark when it comes to using ORMs "in practice".