Importance of "Out of Stock quantity buffer on Amazon" option?

Importance of "Out of Stock quantity buffer on Amazon" option?

Go to the App >> Click on Configuration >> Go to App setting

Whenever an Amazon item inventory quantity reaches to entered buffer quantity in the app or less than the corresponding Shopify item, then Shopify inventory will be updated to 0.                                  
For Instance: If you set "5" quantity in the field, when an Amazon item inventory quantity goes below set value or equal to that value then the Shopify inventory will be updated to 0

Note: This will help you to prevent over selling on Amazon.