What does a product "preordered" mean, and how do I make use of it?
"Preordered" is used in the scenario where you as the merchant are expecting to carry a certain product, but may not have it in stock yet. You might allow your customers to order that product, even though they will not receive it immediately.
To mark an item as "Preordered" you can go to Products > Status > Preordered. You can also click on Edit next to the product > scroll down to Product Status > Preordered.