How do u prevent what could be considered double spending in NFTs?

Let me start first by checking whether this site

is a trusted source of information?

Then it’s written there

So what prevent the auctioneer from resell it again?
( make a new token pointing to the same file?)

  • He used the example of a receipt, if a marchant signed 2 receipts for the same item u could press charges against him, what about NFT?

-I mean other than tampering or making a slight change, does the “create” or “transfer” functions check if the hash already exists, ie have been minted before? or they just verify it?

(A marchant could sign & seal 2 manual receipts to be only discovered in court, but a computerized system wouldn’t print a 2nd receipt from the beginning)

In one sentence
How does NFTs prevent double spending?or they just don’t?