Packaging quantity is a concept used in the process of book packaging and distribution. Book publishers or book wholesalers will classify and package books according to certain regulations when they box them. The number of packages is the number of books in each box. The number of packages depends on the actual situation, and is decided by publishers or wholesalers according to market demand and logistics and transportation considerations. For example, some common album numbers are 10, 20, 30 and so on. This means that there will be a corresponding number of books in each box.