To begin tracking stock, press Start Tracking Inventory in the Inventory section of an existing product.
In the Inventory section, you will see an automatically-generated SKU value based on the Name value. This SKU is editable by changing or replacing the text in the SKU field.
Next to the SKU is a "Quantity" field. Enter the on-hand total directly, or use the up and down arrows on the right to adjust. When you're ready to set the initial quantity, press the Set button.
Click the Save button at the top left of the Product page to finalize your changes.
The merchant will now see the Quantity value they set.
Merchants can use the Quantity field to manually change the on-hand count at any time. Use the up/down arrows to change the stock quantity, click the Set button, and then click the Save button at the top left to finalize.
Stock quantity will change with sales and returns.
In the event that a merchant has activated the Variants extension, Inventory will be controlled there. A note indicating this will show in the Inventory section.
To read more about Product Variants, click HERE.
Tracking inventory allows you to keep track of what you have in stock, know what needs to be pushed versus what may be in short supply. It helps with reordering, sale planning, and just gives you a better handle on what your store is selling.