Shipment
Magento\Sales\Model\ResourceModel\Order\Shipment
What it does
This resource model handles database operations for order shipments in Magento 2.
Developers use this class when they need to save, load, or manipulate shipment records in the database, including validation that shipments contain items and proper order associations.
It automatically serializes package data and ensures shipments are properly linked to their parent orders before saving.