The counting job is the activity that helps count items that have already been made. An inventory count is a snapshot of the current inventory levels.
As soon as you have taken inventory and specified the quantity on hand, the difference between the quantity counted and the snapshot of on-hand inventory is posted as a loss or gain for the item.
The journal of inventory counts shows the on-hand quantity counted compared to the inventory levels. Each count is given a journal number and date. This lets you view data from earlier counts, specifically which counting journal and voucher the count was posted to, and the date of the count.