It is advisable to execute the Sync process first in dump mode, then test mode before running in live mode.

Dump mode will run the Sync and output the raw data without parsing or translating any fields. This allows you check that the importation of data is correct before making any alterations to your database.

Test mode will load the data from the source file and output the data after parsing and running the translations. This allows you to check the data is imported and translated correctly before making any alterations to your database.

Live mode will update the database with the data from the input source file.