Answer supplement
Ownership includes four functions: possession, use, income and disposition.
With these four abilities, you have full ownership.
But these four powers are often separated. For example, leasing transfers the power of possession and use to the lessee.
But the core power should be the right of disposition, and the other three powers can be transferred, but if the right of disposition is transferred, it marks the complete transfer of ownership.
Generally speaking, the difference is that possession does not necessarily mean ownership, but if you have the right to dispose of it, you must have ownership.
For example, if you lend your things to your friends for free, then you have three rights: possession, use and income.
Who owns it at this time? Of course, it's still you-you have the right to take it back, rent it out, sell it and do whatever you want. That is the right of disposal! Therefore, the right of disposition is the core power and symbol of ownership.
Answer supplement
Your view is wrong.
Not everyone has a book.
Only those who buy books, or those who borrow or rent books, have the right to possess them.
But the right of disposal only belongs to the person who bought it, that is, the owner has the right of disposal. That's what it means.