ERC-721 was the first standardized interface for creating NFTs. It is immutable, transparent in ownership and security, and the most widely used. It will always be the gold standard of a valuable collectible NFT. Although transferable, trying to transfer an entire collection can be slow and inefficient, especially when gas fees are high. ERC-721 also requires a new smart contract to be deployed for each new type of token. Therefore, when you need to mint NFTs in masses, it doesn't make much sense to use this contract.
ERC-1155 is a dual purpose fungible and non fungible token. It was developed by Enjin, to tokenize things like common gaming skins and other commoditized items. It’s faster and more efficient to use in batch token transfers and is considered “the next generation multi-token standard,” as it can be deployed in a single smart contract for an infinite number of token types. The only real draw-back is that the NFT is harder to track in terms of ownership—to save data stored on blockchain ERC-1155 has specifications on the Ethereum logs that have less robust information.