When you buy NFTs, you are buying a digital certificate of ownership of cool, unique digital art and collectibles. This digital certificate gives you the right to brag to your friends and prove to the world that it's yours as well as the right to resell it to others (much like in the real art world).
Many people ask - why would I buy an NFT or Digital Collectable when I can just download the file for free?
Think of it like this … like in the traditional art world, NFTs can increase in value and be traded on the open marketplace. But you can't sell something you don't own.
Yes, anyone can download and view most NFTs for free, but they don’t own it and they can’t gain any value from it without owning the NFT token contract as well.
You can download an image of the Mona Lisa, but you won´t be able to sell it, as you don´t own it!
You are not necessarily buying the bundle of rights that accompany copyright though, for example, solely buying an NFT does not bestow the rights to copy the work and resell copies.