Check and update the reference index, which tracks relations between database records in TYPO3.
Use this tool to verify the integrity of existing references or to rebuild the index to ensure all relations are correctly recorded.

Check: Verifies the reference index and reports issues without making changes.
Update: Rebuilds the entire reference index. This may take some time on large installations.

You can also run the check as a shell script using CLI if the processing takes longer than the PHP max_execution_time allows.

To check the reference index use:
php {binaryPath} referenceindex:update -c

To update the reference index use:
php {binaryPath} referenceindex:update