Royalties in NFTs are typically enforced through smart contracts. When an NFT is sold or transferred, a percentage of the sale price (royalty) is automatically sent to the original creator or rights holder as specified in the smart contract. This mechanism ensures ongoing compensation for artists or creators even after the initial sale of the NFT.
NOTE 1: Technically royalties are optional, and there are marketplaces that allow the buyer to decide whether or not to pay the specified royalties.
NOTE 2: The NFT and corresponding royalty standards are still evolving. Ask your nft minting partner about their smart contract compatibility with other marketplaces.