The document compares inventory features between Odoo 12 and Odoo 13, highlighting improvements in stock forecasting, inventory adjustments, and serial number management. Odoo 13 provides a user-friendly interface for updating quantities, a streamlined process for serial number assignment, and enhanced inventory valuation tracking, which were not available in Odoo 12. It details the steps for performing inventory adjustments and generating reports in both versions, emphasizing the upgrades in Odoo 13.