What is the HD Tune remapping sector count?

When using the HD Tune software, it is possible to see some data in the remapping sector count at the health check, and the HD Tune remapping sector count is yellow. The status is warning, what is the HD Tune remapping sector count?

Remapped sector event count is to map the existing bad sectors to the spare area, that is to say, the hard disk itself hides a small part as a backup, specifically stores the files of bad sectors, and is still able to record. The unit of bad track data, the specific unit is not clear, guess is Mb? The worst is the remaining storage value of the entire hard disk in all startup conditions, the worst time, the threshold value means that below this value, the real physical hard disk bad sectors will appear, and it cannot be repaired.