ERC-721 and ERC-1155 are different token standards that determine the number of copies/additions that exist for an NFT. In the case of ERC-721, that is only one NFT like that, and ERC-721 NFTs are referred to as 1/1 NFTs. ERC-1155 NFTs, on the other hand, have more than one congruent NFTs. Even these NFTs, however, are quite limited in their number.
As you may have inferred, it is quite likely that the ERC-721 NFT is valued more than the ERC-1155 NFT.