In the Tendy admin, going into the products variant screen allows you to see the expected inventory in the "Units in Stock" section. It also shows other stock fields that will affect how stock is being used or viewed.
The Units In Stock field represents the total inventory that is not expected to be sold to a customer due to reserve inventory. So the total inventory will be Reserve Stock plus Units in stock.
Units in Stock will be the field that represents the stock the product has in all other Tendy features such as the inventory snapshot and the audits.
The Active Stock is the amount that can be sold. In the above picture you can see 40 Units in stock and 24 Active stock. This means that only 24 products can be sold from the POS or from online sales. In the image you can see how we arrived at 24 active stock. One of the lots are on (the one with 24 inventory) and the other is off (the one with 16). So only the inventory from Lot 00014549 can be sold.
You might want to disable a lot for a few different reasons such as a recall or just not wanting the newer lot to be sold first.