Everything you need to know about what the Inventory Log is in ERP and how to use it.
The Inventory Log displays any transaction that updates the in-stock quantity of any item or product (as long as it's not a non-inventory item). To view it, from ERP go to Inventory > Inventory Log. 
You can click Apply to see all transactions or use the search by function to choose how you'd like to structure your search - then click Apply.
For example, let's say you want to see the inventory history for a specific SKU. Type in the SKU, click Apply, and you will see all logged transactions of inventory changes for that SKU.
Qty = The quantity you are adding or removing from inventory
B4 INV = The amount in stock prior to the update being made