Hi;

"Validate Inventory", means that , you agree the New Values as a Real Values for the stock (the values given by the physical inventory), and those values will replace the old values of the stock (also called the theoretical stock), and becomes the Real Stock.

This operation is necessary and sometimes mandatory, due to the lost of products following the operations of picking and deliveries, theft, breakage, ...

This operation is performed periodically, to adjust the stock value at its real value.