After entering inventory details for your products in QuickSell, you can control what your customers will be able to see. Your customer will not be able to see the amount of units of inventory for each particular product. However you can control the display settings with regards to out of stock products.
You can showcase out of stock products if you wish to do so. Your customer will then be able to see the out of stock product as highlighted in the image above. The other alternative option is that products that are out of stock will be hidden from your customers. You can control this entire process by toggling the Out of stock visibility switch in the Inventory settings screen. This option will also be available on the global and catalogue level Inventory settings options.