The goods are purchased while being sold. Sometimes there may be more people buying this product, which will cause a shortage of goods. However, the products will be supplemented in the future.
Goods are purchased while they are sold. Sometimes it may be that the product buys more people suddenly, will cause the situation of out-of-stock. But the goods will be filled in later.
Goods are sold and purchased at the same time. Sometimes the number of people who buy this product suddenly increases, which will lead to the situation of stock shortage. But we will make up for the goods in the future.