When you sell something in POS, you can, in POS, change most of the information you have added to a specific item, before you press Pay. This can be usefull if you need to make a quick chance on the price of a product/item, before the costumer pays for the item.
When the item is added to the checkout window, simply tap on it (the text) and it will open.
You can then easily change the quantity, change the price, text and give a discount.
You can also delete a single product/item in the checkout window by clicking the small icon with a trash can next to each item and it will then be removed in the checkout window.
If you want to delete everything or start over, you can click on Clear All in the top right of the checkout window. After that all the products/items and the customer you have added to the order, will be removed.