This shows your the total of quantities in bins for each product and the total quantity on hand for your products. Use this to note discrepancies and for adjustments.
The quantities associated with each bin is not 100% tied to the inventory stored in the system. For example, you can have 100 unit for product a as total inventory, but only 50 of them is stored in a bin. The rest of them is stored in an unknown place . This is allowed to give you flexibility in tracking your inventory in bins. Maybe you only put 50 in a bin and the rest is stilling in a pile to be put away. Maybe before you stock the products, someone walks in and grab a few units and ship them away. As a result of this, when you are doing inventory count, you would need to adjust your total inventory on hand to adjust your inventory values and then adjust the quantities stored in each bin.