SourceItem
Magento\Inventory\Model\ResourceModel\SourceItem
What it does
This resource model handles database operations for inventory source items in Magento's Multi-Source Inventory (MSI) system.
Developers use this class indirectly when working with source item data persistence, as it defines the database table structure and primary key for storing inventory quantities at specific sources.
It maps the SourceItem model to the 'inventory_source_item' table in the database.