Inventory History By Type is the transaction log for your stock. Every sale, receipt, and adjustment in the date range appears as its own line, with the quantity, cost, and price at the time it happened. Use it to reconcile inventory, trace what happened to a part, or hand a full period of activity to your accountant.
Each line shows the Store, a numeric Type code with its plain-English Description (Sale, Receipt), the Part, and the Date. Receipt and Issue hold the quantity in and the quantity out, so a sale shows an Issue quantity and a delivery shows a Receipt quantity. Change To On Order covers adjustments to quantities still on order. Average Cost is the unit cost at the time of the transaction and Extended Cost is that multiplied by the quantity; Price and Sales show the selling side. Vendor and the invoice reference identify where the transaction came from.