In the product form:

  • Actual stock: the units you have now.
  • Out of stock: marks the product as unavailable.
  • Low stock limit: below this number, the product counts as "low stock".

Stock goes down automatically with each sale. Products below the limit appear in the Store block of the Overview.

Tip: set a realistic low stock limit (for example, 5 units) and check the Overview every week. That way you reorder before you run out.