You imagine the library management system as your own private collection room.

"Book storage management" is equivalent to adding some books to your private library. You need to sort out and summarize all kinds of information of these added books, which is warehouse management.

"warehousing return management" means that you bought a book and put it in the library, but you want to return it because of some problems, and these return information needs to be sorted out in the return management;

"Book distribution management" is simply a collection of a series of information, such as who you borrowed the book from, when you borrowed it and when you probably returned it.

"Sales return management" is equivalent to what you sell. Customers need to return it to you because of some quality problems or other problems, or exchange it for a new one, and so on. The record of this information needs sales return management;

"Warehouse information management" is even simpler, which is equivalent to the information record of what is put in your warehouse, where it is put, the specific quantity and so on.