Kettle Database Repository: while using Database repository, all the information regarding jobs and transformation is stored in Database, which is the store of ETL metadata.

You have to provide appropriate credential of database, and create a separate schema to store the data in database. It will create tables in database which will be used by spoon to bring them up into your GUI.

Kettle File Repository: while using File repository, all the information regarding jobs and transformation is stored in a specific location.

One of the best advantage of using File repository is that you can store all your jobs and transformation in a shared location, and schedule a backup of shared disk at regular interval, in this way you can make sure your work is not lost.