When you choose to make the Menu item an Inventory Item you get a few extra options
These options relate to the Product. A new product will be created for each Inventory Item. The Unit chosen here will become the Delivery Unit
When you save the new Item, a Recipe will be created linking the Inventory Item to the Product and one will be input as the amount to be taken out of inventory.
Inventory Items are intended for retail and save you time when creating Items as you can create the Product and recipe at the same time. Normally inventory items are sold as a package of 1. Such as a drink, some gum, packet of chips etc.
It does not add everything about the product. It assumes the other unit amounts are package of 1 and it does not add the supplier or reorder amount for you.
If you have any Retail Items you will see them in this section. You are able to change the price of the item the Barcode and the Tax Code without having to go into each Item Individually